Embattled Syrian President Bashar Assad visited Moscow Tuesday and held “lengthy talks” with Russian leader Vladimir Putin, a Kremlin spokesman announced Wednesday. The Syrian leader’s visit to Russia marks his first foreign trip since the start of the civil war in 2011.

“President of the Syrian Arab Republic Bashar Assad arrived in Moscow on a working visit yesterday evening,” Kremlin spokesman Dmitry Peskov reportedly said. “The talks were rather lengthy and the issues discussed are clear enough. … The President [Vladimir Putin] was informed in detail by the Syrian colleague of the state of affairs in Syria and plans for the future.”

According to a transcript of the meeting published on the Russian government’s website, Assad reportedly thanked Putin for his assistance in preserving the “unity of Syria and its independence.”

“If not for your actions and your decisions, terrorism, which has now spread in the region, would have spread to a much larger territory,” Assad told Putin, according to the transcript. “Most importantly, all this was done within the framework of international law.”

It is not yet clear whether Assad is still in Moscow or has returned to Damascus. News of the meeting between Assad and Putin -- who has described Assad as a close ally and a friend -- could further worry the U.S. and its allies, who have accused Moscow of targeting Assad’s enemies -- including so-called “moderate” Syrian rebels fighting the Islamic State group -- in its airstrikes in Syria, which began last month.

However, the Russian government has consistently denied the allegation, and maintained that it is only targeting positions held by ISIS.

“We are ready to do what we can, not only in the military action to fight terrorism in Syria, but also in the political process,” Putin reportedly said, during the meeting. “Of course, this will be done in close contact with the other world powers and countries in the region that are interested in a peaceful resolution of the conflict.”

The Russian leader also expressed concerns over reports that at least 4,000 fighters from the former Soviet Union were fighting alongside “terrorist” groups in Syria. “We cannot allow them to receive military training and indoctrination, and then turn up in Russia,” Putin added.