Russian President Vladimir Putin and German Chancellor Angela Merkel have agreed in a telephone call to coordinate efforts to work toward peace in Syria, the Kremlin says.

"The desire was expressed to advance the political processes in close coordination with the United Nations, in order to solve the Syrian crisis in the long term," the Kremlin said on January 9.

Merkel and Putin also discussed the formation of a constitutional committee for Syria, which is to work out a new constitution for the war-torn country, repeating issues they covered during a phone call at the end of December and at an October summit in Istanbul involving Russia, Germany, Turkey, and France.

The latest conversation comes amid confusion over plans by the United States for its troops in Syria, where they have been assisting a Syrian Arab and Kurdish alliance fight against Islamic State (IS) terrorists and separately against the government of President Bashar al-Assad.

U.S. President Donald Trump on December 19 said that "after historic victories" against IS, all U.S. troops "all coming back and they’re all coming back now."

That announcement shocked many U.S. lawmakers and international allies, who said a premature withdrawal from Syria would hand Russia and Iran a victory and leave U.S. Kurdish allies at the mercy of Turkish forces also operating in the country.

After the outcry, Trump's national security adviser, John Bolton, said on January 6 that the decision to withdraw U.S. troops was conditional on Turkey ensuring the safety of Kurds in Syria.

During an unannounced visit to Iraq on January 9, U.S. Secretary of State Mike Pompeo attempted to reassure the U.S.-backed Kurdish fighters in Syria that their safety will be ensured after the U.S. troop withdrawal.

"These have been folks that have fought with us, and it's important that we do everything we can to ensure that those folks that fought with us are protected," Pompeo said of the Kurds while visiting Irbil, the capital of Iraq's autonomous Kurdistan region, after talks in Baghdad.

Turkey, which accuses many of the Kurdish fighters with having links to separatists in Turkey, has vowed to clear northern Syria of Kurdish fighters after the pullout of the 2,000 U.S. troops.

With reporting by dpa and TASS