The U.S. does not believe Bashar al-Assad will stay in power, State Department spokesperson Heather Nauert said Tuesday, adding it may take time for the Syrian people to be able to vote for their next leader.

"We remain committed to the Geneva process. We believe that the future of Syria will not include Bashar al-Assad, but that is ultimately up to the Syrian people and the Syrian voters to decide," Nauert told reporters in a press briefing.

The Geneva II Conference on Syria was a UN-backed international peace conference on the future of Syria with the aim of ending the Syrian civil war by bringing together the Syrian government and the opposition to discuss clear steps towards a transitional government.

Asked whether the U.S. is prepared to accept Assad’s continued rule until Syria’s next scheduled presidential election in 2021 as reported Monday by The New Yorker magazine, Nauert denied the claim.

"It's not up to the United States to ultimately decide. That is up to the Syrian people," she stressed.

Turning to a question about Russian statements on the withdrawal of their forces from Syria, Nauert said Russia may consider its job to be done in Syria, but the U.S.-led global coalition will continue operating in the country.

"There are still pockets of ISIS. The country still needs to be stabilized. We were just talking about rubble removal and we were talking about de-mining," Nauert noted, referring to the Islamic State of Iraq and Syria, another name for Daesh.

"If Russia chooses to pull out, certainly that is its choice to do so," Nauert added. "But we continue to work through all our partners to try to stabilize the country."

Last week, the commander of the Russian forces in Syria, Colonel General Sergei Surovikin, said Russia will withdraw its 23 combat aircraft, two helicopters, special forces units, military police and area security personnel from Syria following an announcement by Russian President Vladimir Putin declaring “victory” in Syria during a surprise visit to a military base there.

On the other hand, Some were welcomed by small crowds holding patriotic banners in ceremonies with Soviet-era music in the background. Others were greeted by high placed military officials. On a surprise visit to Syria on Monday, Putin ordered the start of a pullout of Russian troops, saying their task in the war-torn country had been largely completed.

Russian state television showed images of servicemen back in the far corners of their country, from Dagestan in the North Caucasus to Ivanovo in Central Russia and Murmansk inside the Arctic Circle, throughout the day. 

"The battalion of military police from the southern military district (of Russia) deployed to the Syrian Arab Republic has been flown by two military planes to Makhachkala (the capital of Dagestan) airport," the Russian army said in a statement.