CAIRO: A senior US official flew into Cairo early Monday, hours after Egypt's prosecutor ordered the freezing of assets belonging to 14 top Islamic leaders.
Under Secretary of State Bill Burns, the first US official to visit since the overthrow of President Mohamed Morsi, is scheduled to stay there until Tuesday, the US State Department said.
Burns will push for "an end to all violence and a transition leading to an inclusive, democratically elected civilian government" at meetings in Cairo with various parties, it said.
His visit comes as the new regime applies increasing pressure on Morsi's Muslim Brotherhood, already in disarray with key figures detained, on the run or keeping a low profile.
It also comes amid international concern over the detention of Morsi, Egypt's first freely elected president, who was toppled in a popularly backed military coup on July 3.
The US administration has still not decided whether Morsi was the victim of a coup, which would legally require a freeze on some $1.5 billion in vital military and economic US assistance to Cairo.
On Sunday, two influential Republican US lawmakers, Senator Lindsey Graham and Senator John McCain, urged the administration to cut the aid in response to the coup.
Also Sunday, the European Union's foreign policy chief Catherine Ashton called for a swift return to civilian, democratic rule and the release of political detainees.
The Brotherhood has refused to join the new government headed by caretaker Prime Minister Hazem al-Beblawi, who is pushing ahead with talks on forming his cabinet.
The ultra-conservative party Al-Nur also confirmed it will not join the interim government. Spokesman Nader Bakkar told AFP: "We would participate only in an elected government."
On Sunday, Beblawi appointed a former ambassador to Washington, Nabil Fahmy, as foreign minister, and veteran World Bank economist Ahmed Galal as finance minister.
Prominent liberal leader Mohamed ElBaradei, 71, was sworn in as interim vice president for foreign relations.
Beblawi is expected to unveil his full cabinet Tuesday or Wednesday. He says his priorities are to restore security, ensure the flow of goods and services and to prepare for parliamentary and presidential elections.
The assets freeze against nine senior Brotherhood figures is part of an investigation ordered by public prosecutor Hisham Barakat.
Those targeted include leader Mohamed Badie and five others from groups including ex-militant faction Gamaa Islamiya, judicial sources said.
It relates to four deadly incidents since Morsi's overthrow, including clashes in Cairo last Monday in which dozens died.
The order comes a day after prosecutors received criminal complaints against Morsi, Badie and other senior leaders, with a view to launching a formal investigation.
The complaints include spying, incitement to violence and damaging the economy.
Morsi has not been seen in public since his ouster.
In his first public comments since deposing the leader, military chief General Abdel Fattah al-Sisi said the army acted after Morsi rejected a referendum on his presidency.
"The armed forces, with all its personnel and its leaders, decided without reserve to be at the service of its people and to empower their free will," he said in a statement.
The interim leaders say Morsi is being held in a "safe place, for his own safety".
But the United States and Germany have already called for his release. Washington has also condemned the wave of arrests of Brotherhood members.
The prosecutor said on Sunday that 206 out of a total of 652 people arrested over fatal clashes in the past week had been released on bail.
Fighting erupted Sunday between gunmen and the army near Israel, in the Sinai Peninsula, which has witnessed a number of deadly attacks in the past week, security sources said.
But the worst violence since the military coup took place outside the elite Republican Guard's Cairo headquarters on July 8.
On that day, 53 people, mostly Morsi supporters, were killed in what the Brotherhood described as a "massacre" by the security forces.
Interim president Adly Mansour has set a timetable for elections by early next year, following a roadmap drafted by the military.
During his single year of turbulent rule, Morsi was accused of concentrating power in Brotherhood hands, sending the economy into free fall and failing to protect minorities.
But his supporters say his ouster was an affront to democracy, and the Brotherhood is planning more mass protests on Monday, including at the Republican Guard headquarters.
Rival protests are also planned in Tahrir Square and at the Ittihadiya presidential palace by the main coalition that had called for Morsi's resignation.