Trump warns he has entered 'deciding mode' on Iran, says 'big things' are in store

US President Donald Trump warned on Sunday that he had entered a critical decision phase in the ongoing war with Iran, cautioning that major developments would occur if Tehran failed to change its conduct.

"My question is if and when do I blow the entire nation up? They had better behave," Trump told Fox News, detailing his approach to the war.

The US president described his current options as wiping the country out, allowing it to "rot" economically, or negotiating a deal, adding that “very big things are going to be happening in the not-so-distant future.”

BREAKING: President Trump told Fox News Chief Foreign Correspondent @TreyYingst that he is in a “deciding mode” and "very big things" are going to happen in the near future regarding the US-Iran war.

Trump said, "My question is, if and when do I blow the entire nation up? They… pic.twitter.com/JcAXh9QN84

— Fox News (@FoxNews) September 20, 2026

When asked about the UN General Assembly high-level week, which starts on Monday, Trump signalled a willingness to engage diplomatically, saying he would "probably be open" to meeting with Iranian President Masoud Pezeshkian.

Addressing wider regional hostilities, Trump said Washington remained in constant communication with Yemen's Houthis following their recent ballistic missile attacks targeting Saudi Arabia, asserting that the group agreed to avoid fighting American forces.

Iran warns regional states will be 'considered complicit' if US strikes resume

Iran received information that the United States, with the backing of some regional countries, was preparing to resume actions against Tehran, the Khatam al-Anbiya Central Headquarters, the Islamic Revolutionary Guard Corps' (IRGC's) joint military command, said in a statement on Sunday, according to state media.

🔴 Iran’s Khatam al-Anbiya Central Headquarters warns US against any aggression, saying US bases will face painful attacks.

Follow: https://t.co/oa9JV4ikYQ pic.twitter.com/ba2yxDSCSr

— Press TV 🔻 (@PressTV) September 20, 2026

The military said that any US had been given a "green light" by unnamed regional countries at a joint meeting in Europe to resume action against Tehran.

According to state media, the military added that any US attack would lead to Iranian retaliation "without any limitations or considerations" on US bases and interests. Regional countries involved in any US attack on Iran, the military said, should not expect restraint from Tehran's armed forces and would be considered complicit and parties to the conflict.

Separately, Iran's Secretary of the Supreme National Security Council, Mohsen Rezaei, stated that US President Donald Trump had waged a foolish war on Iran and was foolishly continuing it, IRNA reported.

Rezaei added, however, that Iran “stands ready to give a stronger and more painful response should the US resume military aggression.”

Top security official: Trump foolishly continues war, but Iran fully ready for self-defensehttps://t.co/3LWLeV8Se6 pic.twitter.com/HU0zOnTs8v

— IRNA News Agency ☫ (@IrnaEnglish) September 20, 2026

“We have fully prepared ourselves for a decisive war, and the US’ military vulnerabilities are completely known to us. And we are far better prepared this time,” he said, according to IRNA.

The secretary further noted, “Netanyahu plunged Trump into a quagmire.” It was and is in the benefit of the US to accept Iran’s conditions and end the war because the more the conflict drags on, the worse the US’ situation will become, IRNA quoted him as having said.

Iran's Army Ground Forces Commander Brigadier General Jahanshahi also noted separately that Tehran's border units remained deployed and on constant alert in various border areas, Press TV reported.

🔴 Iran’s Army Ground Forces Commander Brigadier General Jahanshahi:

🔺Iranian Army border units remain deployed and on constant alert in various border areas, prepared to counter any potential threats and protect the country’s security and territorial integrity. pic.twitter.com/npBqzXU6HU

— Press TV 🔻 (@PressTV) September 20, 2026

Jahanshahi added that the units were prepared to counter any potential threats and to protect the country's security and territorial integrity.

Ghalibaf vows to 'deal devastating blows' to enemy at 'critical moment'

Iran's Parliament Speaker Mohammad Bagher Ghalibaf said "one must both fight and negotiate." He added, “This means at the critical moment we must push the enemy back and deal them devastating blows using our full military might,” Al Jazeera reported.

Iran's Parliament Speaker Mohammad Bagher Ghalibaf says “one must both fight and negotiate” as the nearly seven-month war with the United States drags on.

🔴 LIVE updates: https://t.co/qJleYbnwN8 pic.twitter.com/3qwO4fZLHx

— Al Jazeera English (@AJEnglish) September 20, 2026

“However, once we have achieved significant success on the battlefield and the enemy is in a position of weakness, we must use diplomacy to consolidate these gains,” Ghalibaf said.

The speaker noted that Iran’s position in negotiations was “entirely clear, rational, and non-negotiable.”

Earlier, Ghalibaf said the Strait of Hormuz will remain closed until the US fulfils its commitments under a now-defunct peace deal signed in June, Al Jazeera reported.

Iran's Parliament Speaker Mohammad Bagher Ghalibaf says the Strait of Hormuz will stay closed until the US fulfils its commitments under the now-defunct peace deal that was signed in June.

🔴 LIVE updates: https://t.co/qJleYbmYXA pic.twitter.com/y6TiZv3kZT

— Al Jazeera English (@AJEnglish) September 20, 2026

Flames, smoke seen near Riyadh airport, Houthis claim attacks on Saudi capital

Yemen's Houthis said they attacked "sensitive" sites in the Saudi capital Riyadh on Saturday with missiles and drones, hours after flames and a large ​plume of smoke were seen near the city's main airport.

Saudi Arabia had sent alerts overnight warning of potential danger around Riyadh, amid an escalation in attacks ‌by the Houthis in the kingdom.

Reuters video and photographs showed a huge pillar of black smoke rising in the area, with the airport highway, main terminal building and other facilities in the foreground. At one point in the video, flames were visible rising from behind what appeared to be fuel tanks.

While the Houthis have launched repeated attacks against Saudi Arabia since July, Saturday's claim appeared to be their first reported strike on Riyadh since ​the current escalation began.

The Houthis did not specify what they had targeted in Riyadh, but said they had also attacked an Aramco facility in the Red Sea city of ​Yanbu, a key Saudi oil export hub.

They said the operation came as a response to an attack in the Yemeni capital Sanaa.

The Saudi-led military ⁠coalition fighting the Houthis said its air defences had destroyed a missile fired by the Yemeni group toward Riyadh early on Saturday.

In a statement, the coalition also said it had foiled ​attacks targeting civilians in the Saudi cities of Bish and Farasan in the southwest and Taif in the west, as well as Yanbu on the Red Sea coast. It did not say whether ​there was any damage.

Read: Houthis threaten ‘decisive’ response if Pakistan, Türkiye intervene in Yemen

Saudi civil defence sent the alerts by phone overnight for potential danger of aerial attacks in Riyadh and the city of Al-Kharj east of the capital, before issuing an all-clear on Saturday morning. A Reuters journalist in Riyadh's Olaya area heard booms before the all-clear was sent.

Although some alerts had been issued in Riyadh this year after the start of the US-Iran war, these were the first since the escalation with the ​Houthis began in July.

The fighting between the Houthis and Saudi Arabia has developed as a new theatre of conflict in the wider war that began with US and Israeli strikes against Iran ​at the end of February. US President Donald Trump has rebuffed Saudi requests for direct US military intervention against the Houthis.

UN, Gulf Cooperation Council chiefs condemn Houthi attacks on Saudi Arabia

UN Secretary-General Antonio Guterres and Gulf Cooperation Council (GCC) head Jasem Mohamed Albudaiwi on Saturday strongly condemned Houthi attacks on Saudi Arabia, warning that the group’s targeting of civilian objects poses a severe threat to regional peace and security.

Guterres received Albudaiwi in New York on the sidelines of the GCC chief’s participation in the 81st session of the UN General Assembly, according to a statement from the GCC Secretariat General.

“Both officials strongly condemned the Houthi militia’s attacks against the Kingdom of Saudi Arabia and their deliberate targeting of civilian objects, underscoring the severe threat these hostile actions pose to regional peace and security,” it said.

Read more: Houthis fire 'ballistic missile' at Riyadh

The two officials also reviewed cooperation between the GCC and the UN, and discussed ways to deepen collaboration in areas of shared interest. They exchanged views on geopolitical developments and discussed regional issues and diplomatic efforts to resolve them.

Guterres commended “the substantial progress and prosperity achieved by GCC member states” and praised their contributions to promoting lasting stability worldwide.

US urges Americans to reconsider travel to Middle East amid rising tensions

The US on Saturday urged Americans outside the Middle East to seriously reconsider travel to and through the region, citing a complex security environment and the potential for rapid escalation.

The State Department's Travel.Gov account on a US social media platform said Americans in the Middle East should exercise heightened vigilance and be prepared for possible flight cancellations, airspace closures and other travel disruptions.

“Due to tensions in the Middle East, the security environment remains complex with the potential for unforeseen escalation,” it said.

It warned that Houthis have engaged in hostilities against Saudi Arabia, including attacks involving civilian airports, and said the conflict “has the potential to escalate rapidly.”

Also read: Italian aircraft hit during air base attacks in Saudi Arabia

Americans traveling to or from the region were advised to monitor information on airport and airline operations.

The State Department also warned that US diplomatic facilities, including those outside the Middle East, have been targeted and that Iran and groups supporting it may target other US interests overseas or locations associated with the US and Americans worldwide, including US businesses and other institutions.

Trump cuts short Camp David stay amid rising Middle East tensions

US President Donald Trump cut short his weekend stay at Camp David and was expected to return to the White House late on Saturday, according to a White House pool report.

The White House updated the president’s schedule to show his return to Washington on Marine One, with the presidential helicopter expected to arrive at the Ellipse at about 7 pm local time (2300GMT), USA Today reporter Joey Garrison reported in a pool report.

No reason was given for the change to Trump's schedule.