Russian Foreign Minister Sergei Lavrov said he welcomes U.S. President Donald Trump's recent pledge to pull U.S. troops out of Syria "very soon" now that the Islamic State (IS) militant group has been largely defeated there.

Lavrov told reporters in Moscow on April 2 that Russia had recently seen what he called "worrisome" signs that U.S. troops were "getting deeply entrenched" in areas east of the Euphrates River that they recently helped liberate from IS.

Trump's statement last week shows that "he is committed at least to the previous promises the United States will leave Syria after victory over the Islamic State," Russian state-run news agency TASS quoted Lavrov as saying.

Russia and Syrian President Bashar al-Assad have been urging the United States for months to pull its 2,000 or so troops out of Syria, maintaining that their presence on Syrian territory is a violation of international law.

Assad frequently points out that he did not invite U.S. troops to join the seven-year civil war like he did when he invited Russian forces in 2015 and Iranian forces and militias since the beginning of the war in 2011.

In response to Russia's calls to leave Syria in recent months, top U.S. officials have said they intended to keep U.S. troops there as long as needed to protect U.S. allies in the war-torn country and ensure that IS does not make a comeback in its former Syrian strongholds.

Former U.S. Secretary of State Rex Tillerson, who Trump fired last month citing significant policy differences, argued in January that U.S. forces must remain engaged in Syria not only to prevent IS and Al-Qaeda from returning, but to deny Iran a chance to "further strengthen its position in Syria."

Pentagon leaders have made similar statements. Defense Department spokesman Major Adrian Rankine-Galloway said on April 2 that "Our mission has not changed... We are continuing to implement the president's strategy to defeat [IS]."

But Trump's statement on March 29 -- telling supporters in the U.S. state of Ohio that "we'll be coming out of Syria, like, very soon. Let the other people take care of it now" -- suggested Trump may be thinking differently about Syria than some of his top advisers.

In another sign Trump may be mulling a pull-out, The Wall Street Journal recently reported that he is holding up $200 million in U.S. funding earmarked to go toward stabilizing areas of eastern Syria recaptured from IS.

Lavrov's comments welcoming Trump's eagerness to leave Syria come as Russia and Syria have been clearing out the last remnants of armed rebel groups that once largely controlled the Damascus suburb of eastern Ghouta through a series of negotiated pull-outs.

The Russian military and Syrian state media reported on April 2 that the largest rebel group, Jaish al-Islam (Army of Islam), has started evacuating from the area's last holdout town, Douma.

The SANA news agency said two buses carrying the rebels left Douma heading for Jarablus, a town in north Syria shared between rebels and Turkish forces.

The Syrian Observatory for Human Rights, a war monitoring group, also reported that the last rebels are leaving Douma, handing Syria and Russia their biggest potential win since they regained control of Syria's largest city, Aleppo.

With reporting by AP, AFP, TASS, and Interfax

