U.S. President Donald Trump has spoken by phone with Russian President Vladimir Putin, the White House said, adding that Syria, Iran, North Korea, and Ukraine were on the agenda.
Trump's November 21 phone call with the Russian president came a day after Putin met with Syrian President Bashar al-Assad at the Black Sea resort of Sochi ahead of a summit on November 22 in the same location with Turkey and Iran.
In a statement, the White House said that Putin and Trump spoke for about an hour.
The conversation came after Trump and Putin spoke informally several times earlier this month when they attended a summit in Vietnam, where they issued a joint statement on November 11 agreeing that a political solution was needed on Syria and that they would continue efforts to fight the Islamic State (IS) militant group.
Trump at the time called that joint document "extraordinarily important."
The White House said that, during their November 21 phone conversation, "the presidents affirmed their support for the joint statement of the United States and the Russian Federation, issued at the Asia-Pacific Economic Cooperation Summit on November 11."
Trump and Putin during their phone call voiced support for "the UN-led Geneva process to peacefully resolve the Syrian civil war, end the humanitarian crisis, allow displaced Syrians to return home, and ensure the stability of a unified Syria free of malign intervention and terrorist safe havens," the White House said.
UN-sponsored negotiations aimed at fostering a political solution to the conflict are due to resume in Geneva on November 28.
Syrian opposition groups are expected to meet in Saudi Arabia on November 23 in an attempt to create a single representative body for the latest round of talks in Geneva.
According to a Kremlin statement earlier on November 21, Assad was invited to Russia to get him to agree to potential peace initiatives drafted by Russia, Iran, and Turkey, the Kremlin said in a statement.
Russia and Iran have given crucial military and diplomatic backing to Assad's government throughout the war, which began with a government crackdown on protesters in 2011.
Turkey supports rebels who want to oust the Syrian president.
Assad and Putin refer to the IS group and most of his other opponents as terrorists.
The war has killed more than 330,000 people, created more than 6 million refugees, and forced some 5 million people to become internally displaced.
Putin briefed Trump in the phone call about his talks with the Syrian leader and plans for a political settlement in Syria, saying that Damascus was in favor of finding a political solution to the six-year war, the statement said.
Assad had confirmed to Putin his "commitment to the political process, and conducting constitutional reform and presidential and parliamentary elections," the statement said.
Western powers have called for Assad to step down since the war broke out in 2011, and the Syrian president's fate has been a stumbling block in previous peace talks.
It was the second time Assad has traveled to Russia to meet with Putin in the course of the war.
The first was in October 2015, shortly after Russia launched its air and ground campaign in Syria to beef up Assad's forces.
The presidents of Russia, Turkey, and Iran were scheduled to meet in Sochi on November 22 to discuss Syria.
The meeting will focus on reducing violence in Syria and matters related to the delivery of humanitarian aid to the region, officials said.
Moscow, Ankara, and Tehran are sponsoring separate talks in the Kazakh capital, Astana, that involve warring sides in the war and focus on battlefield issues, such as the formation of de-escalation zones in key regions of Syria.
The White House also said Trump and Putin on November 21 "affirmed the importance of fighting terrorism together throughout the Middle East and Central Asia" and agreed to look into ways to step up cooperation in the fight against IS, Al-Qaeda, the Taliban, and other terrorist groups.
The two leaders also discussed ways to implement "a lasting peace in Ukraine," as well as the need to keep up international pressure on North Korea "to halt its nuclear weapon and missile programs," the White House said.