Palestinian president Mahmud Abbas visits Russia on Monday in a bid to secure Russian President Vladimir Putin's support following Washington's recognition of Jerusalem as Israel's capital.

Israel issued stark warnings on Sunday over Iran's presence in neighboring Syria after a confrontation threatened to open a new and unpredictable period in the country's seven-year civil war.

U.S. President Donald Trump said in an interview published on Sunday that he was "not necessarily sure" Israel was seeking to reach a peace agreement with the Palestinians.

Eleven Turkish soldiers were killed on Saturday, including two military personnel when a helicopter was downed, in the bloodiest day in Ankara's offensive against a Kurdish militia in northern Syria.

United Nations Secretary-General Antonio Guterres has called for an immediate de-escalation in Syria after Israel carried out raids inside the war-torn country.

Syrian regime air strikes killed six civilians including two children overnight in Eastern Ghouta after a day of respite from deadly bombardment of the rebel enclave, a monitor said Sunday.

Israel's Prime Minister Benjamin Netanyahu said Sunday that Israeli air strikes in Syria the previous day were a "heavy blow" to Iranian and Syrian forces in the war-torn country.

Israeli Prime Minister Benjamin Netanyahu has vowed not to allow Iran to establish a military presence in Syria, after Israel launched air raids on what it said were Iranian targets in its Arab neighbor.

The United States has backed Israel for its strikes on what Tel Aviv called Iranian positions inside Syria, blaming Iran for escalating violence in the war-wracked country.

Russia on Saturday called for "restraint" of all parties in Syria and said it considered risking the lives of Russian soldiers "absolutely unacceptable" following large-scale Israeli air strikes inside Syria. 

"We strongly call on all sides involved to show restraint and avoid all acts that could lead to complicating the situation further," the Russian foreign ministry said in a statement published Saturday.