Donald Trump will host Saudi Arabia's crown prince in Washington Tuesday, giving the president a receptive audience to denounce rival Iran and a chance to take stock of significant changes the prince is engineering in the kingdom.

As Russia-backed Syrian regime forces chip away at what remains of the last opposition bastion outside Damascus, experts say the future looks bleak for rebels there.

Syria's Kurds vowed to fight to retake the Kurdish enclave of Afrin after Turkey-led fighters on Sunday seized control of its main city two months into a offensive.

Syria's President Bashar al-Assad met with soldiers in Eastern Ghouta on Sunday, the presidency said, in the leader's first trip to the former rebel enclave outside Damascus in years.

Syria state television broadcast photos of the president dressed in a shirt and jacket surrounded by soldiers, some perched on a tank behind him, in an unspecified part of Eastern Ghouta.

A Palestinian stabbed and seriously wounded an Israeli security guard in Jerusalem's Old City on Sunday before being shot dead by a police officer, Israeli authorities said.

Donald Trump will host Saudi Arabia's crown prince in Washington Tuesday, giving the president a receptive audience to denounce rival Iran and a chance to take stock of significant changes the prince is engineering in the kingdom.

An Arab Israeli suspected of having stabbed to death a rabbi near a settlement in the occupied West Bank last month has been arrested, Israeli authorities said Sunday. 

More than 1,500 Kurdish fighters have been killed in a two-month assault by Turkish forces and allied Syrian rebels on the Kurdish enclave of Afrin, a monitor said Sunday.

Israel's military carried out an air raid overnight against an underground Hamas facility in the Gaza Strip and destroyed a separate tunnel under construction that could be used for attacks, it said Sunday.

Turkey's flag was flying in Syria's Afrin on Sunday after Turkish troops and Ankara-backed rebels chased out Kurdish militia forces to seize control of the northern city.

In a major victory for Ankara's two-month operation against the Kurdish People's Protection Units (YPG) in northern Syria, Turkish-led forces pushed into Afrin apparently unopposed, taking up positions across the city.