Several European countries including Germany and France have halted arms exports to Turkey over the offensive and some like Italy are pushing for a formal EU ban.
But, with some EU states urging caution so as not to inflame already tense ties with Turkish President Recep Tayyip Erdogan, foreign ministers meeting in Luxembourg look unlikely to agree tough concrete actions.
Kurds announce deal with Damascus as Turkey pushes deep into Syria
"We don't have magic powers but what we can do is put all pressure possible to stop this action," Spanish Foreign Minister Josep Borrell told reporters as he arrived for the meeting.
Spain would back a Europe-wide arms embargo, Borrell said, but warned it would be hard to get the unanimous support of all 28 EU states.
Germany's Heiko Maas said the offensive by NATO member Turkey threatens to upend progress towards a political solution to Syria's civil war, with the Kurds now joining forces with the government of President Bashar al-Assad.
But he said "it is important to remain in dialogue with Turkey in order to be able to influence it.
"If that is not successful, we will have to reserve the right to take further measures," he said.
Turkey's assault, which has seen airstrikes, shelling and a ground incursion, has killed scores of civilians and fighters since its launch on Wednesday.
The EU last week issued a statement in the name of all 28 member states to condemn the offensive, warning it risked unleashing a humanitarian disaster and could undermine the fight against the militant Islamic State group.
French Foreign Minister Jean-Yves Le Drian said the most important thing was for Monday's meeting to send a strong message to Turkey.
Paris also wants the US-led international coalition against IS -- of which Turkey is a member -- to meet to discuss the crisis, Le Drian said.
Washington has ordered the withdrawal of almost its entire ground force in Syria, leaving the Kurds feeling abandoned by their ally in the fight against IS.
The Turkish offensive creates huge headaches for NATO, with several countries highly critical and even imposing arms embargoes on a fellow alliance member.
Luxembourg Foreign Minister Jean Asselborn called the situation "unbelievable", asking what would happen if Syria launched a counter-attack.
"Would Article 5 be triggered?" he said, referring to NATO's mutual self-defence clause under which an attack on one member is an attack on all.
Turkey military assault could displace 400,000 in Syria: UN
NATO chief Jens Stoltenberg held talks on Friday with Erdogan and his foreign minister Mevlut Cavusoglu, sharing his "very serious concerns" about the offensive.
Cavusoglu said Spain had told Ankara that as a result of the assault, it would withdraw its Patriot missile batteries from Turkey -- originally deployed to help it defend itself against IS attacks -- when the current mission ends in December.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ