Trump tweets to Syria, Russia and Iran: Stop bombing in Idlib

US President Donald Trump on Sunday told Syria and Russia to stop "bombing the hell" out of Syria's last militant stronghold of Idlib.

"Hearing word that Russia, Syria and, to a lesser extent, Iran, are bombing the hell out of Idlib Province in Syria, and indiscriminately killing many innocent civilians. The World is watching this butchery. What is the purpose, what will it get you? STOP!" he said on Twitter, shortly before he was to depart for a state visit to Britain.

Kremlin spokesman Dmitry Peskov rebuffed Trump's criticism on Monday, saying that its action in the province was justified because militants are using Idlib as a base to launch attacks against civilian and military targets.

Trump's comments came after Syrian NGOs on Friday decried international inaction in the face of mounting violence in the northwestern region, AFP said.

The recent bombardments by Syrian and Russian forces in northwest Syria have killed dozens of civilians and pushed 300,000 people towards Turkey's border, the NGOs said at a news conference in Istanbul.

Still, the Trump administration has made it clear to the Kremlin that the US fully supports Israeli air strikes in Syria while Iranian forces, Hezbollah and pro-Iranian militias are operating in the country, a senior US official told columnist Barak Ravid, writing in Axios on Sunday.

The US official added that the broader message to Russia is that withdrawal of Iranian and Iranian-backed forces from Syria isn't just an Israeli demand, but an American one too.

The Syrian Observatory for Human Rights said on Friday that almost 950 people had been killed in the latest clashes in Idlib.

A September deal was supposed to avert a full-out government offensive on the province and adjacent areas held by Syria's former al-Qaeda affiliate Hayat Tahrir al-Sham.

Still, the militants have refused to leave the area and the deal is on the verge of collapse as Syrian and Russian forces allied to Syria's President Bashar al-Assad ramp up air strikes and rocket fire.

Iranian fighters and Hezbollah paramilitary forces are also stationed in Syria to back the Assad government.

The worsening unrest in Idlib comes with tensions soaring between Iran and the United States.

The stand-off has been simmering since the US last year withdrew from the 2015 nuclear treaty Iran reached with major world powers.