Syrian regime forces on Wednesday penetrated the strategic town of Saraqeb in Idlib province, a war monitor said.

"Regime forces have entered Saraqeb, after hundreds of jihadists and allied forces retreated north of the town," Rami Abdel Rahman, head of the Syrian Observatory for Human Rights, told AFP.

Eight humanitarian aid organizations on Wednesday called for an immediate ceasefire in northwestern Syria, where hostilities have displaced hundreds of thousands of people in the past two months.

The Syrian regime -- backed by Russia -- has carried out an intense air offensive against jihadists and rebels, enabling it to reclaim several towns and villages in the Idlib region despite a freshly-brokered truce.

Iran's supreme leader Ayatollah Ali Khamenei predicted Wednesday that Donald Trump would outlive the U.S. president's controversial proposals for Israeli-Palestinian peace. 

Syrian regime forces Wednesday pressed on with their offensive in the northwest that has displaced half a million people, despite heightened tensions with Turkey.

Turkish President Recep Tayyip Erdogan urged Syria on Wednesday to withdraw its troops from its military observation posts in northwestern Idlib province where clashes have intensified in recent days. 

Syrian militants affiliated with groups such as al-Qaida and the Islamic State group are currently being sent by Turkey to fight on behalf of the U.N.-supported government in Libya, according to two Libyan militia leaders and a Syrian war monitor.

Both sides in Libya's civil war receive equipment and backing from foreign countries. But Turkey, which has long trained and funded opposition fighters in Syria and relaxed its borders so foreign fighters joined IS, has in recent months been airlifting hundreds of them over to a new theater of war in Libya.

The Islamic State group has maintained its capabilities in Syria despite the death of its chief Abu Bakr al-Baghdadi, an independent US government watchdog said in a report on Tuesday.

Israeli aircraft struck Hamas positions in Gaza early Wednesday, the military said, after Palestinians in the enclave launched projectiles and explosive balloons at the Jewish state.

Secretary-General Antonio Guterres on Tuesday emphasized the U.N.'s role as the guardian of international law in the Israeli-Palestinian conflict, days before U.S. President Donald Trump's son-in-law is to present a new Mideast peace plan to the Security Council.

Turkish President Recep Tayyip Erdogan said Turkey will not allow Syrian forces to gain ground in the last opposition stronghold of Idlib, in comments published Tuesday, a day after eight Turks died in regime fire.

"Syria is right now trying to buy time by driving those innocent and grieving people in Idlib toward our borders. We will not allow Syria the opportunity to gain ground there," Erdogan said in quotes published by the Hurriyet newspaper and broadcaster NTV.