Palestinian refugees living in Syria have maintained their neutrality in the Syrian conflict and that position should be respected, a United Nations official said in New York on Friday.

Filippo Grandi, commissioner general for the UN Relief and Works Agency, said the violence in Syria had so far spared the 500,000 Palestinian refugees in the country because of their neutrality. The refugees themselves have been asked not to get involved in the conflict.

"In the current situation, it's essential that the neutrality be maintained and respected," Grandi told a news conference at UN headquarters in New York.

He said UNRWA had closed some schools for Palestinian children in Homs and other cities after the situation became too dangerous for them to attend classes.

UNRWA is charged with caring for the estimated 5 million Palestinian refugees in the Middle East.

UN-Arab League envoy Kofi Annan met Syrian President Bashar Assad on Saturday to press for a political solution to Syria's year-long uprising and bloody crackdown in which thousands of people have been killed.

Syrian state television said there had been a "positive atmosphere" at the talks, but gave no details.

The diplomacy led to no immediate let-up in violence. Syrian forces shelled the northwestern city of Idlib, wounding 20 people, while three soldiers were killed when rebels attacked armored vehicles as they tried to advance, the Syrian Observatory for Human Rights said.