Biden spoke Tuesday for about two hours with Russian leader Vladimir Putin in a video call during which the president was expected to seek a diplomatic solution for Russia assembling tens of thousands of troops near the Ukraine border for a possible invasion, in addition to telling Putin the U.S. is ready to impose austere sanctions.

The call went on from about 10 a.m. to 12 p.m. Washington, D.C. time. 

Putin took the call from his residence in the Russian resort town of Sochi. He said, “Greetings, Mr. President!” as the call kicked off, to which Biden responded, “Good to see you again.

According to a White House statement on the call, Biden “voiced the deep concerns of the United States and our European Allies about Russia’s escalation of forces surrounding Ukraine and made clear that the US and our Allies would respond with strong economic and other measures in the event of military escalation.”

The U.S. President went on to reiterate “his support for Ukraine’s sovereignty and territorial integrity and called for de-escalation and a return to diplomacy.”

Putin was expected to demand guarantees from Biden that the NATO military alliance will never expand to include Ukraine, which has long sought membership.

“We’ve consulted significantly with our allies and believe we have a path forward that would impose significant and severe harm on the Russian economy,” White House press secretary Jen Psaki said Monday. “You can call that a threat. You can call that a fact.”

U.S. intelligence officials have determined that Russia has amassed 70,000 troops near the Ukraine border and has made preparations for a possible invasion early next year.

Ukrainian authorities say Russia is now also sending tanks and snipers to war-torn eastern Ukraine to “provoke return fire,” according to the AP. 

Ukraine’s Defense Ministry alleged that Russia is holding “training camps under the leadership of regular servicemen of the Russian Armed Forces.”

The Kremlin hasn’t commented on the allegations.

Beyond the tension with Ukraine, the two presidents discussed “the US-Russia dialogue on Strategic Stability, a separate dialogue on ransomware, as well as joint work on regional issues such as Iran,” according to the White House. 

Later Tuesday afternoon, Biden is scheduled to speak with French President Emmanuel Macron, British Prime Minister Boris Johnson, and Italian Prime Minister Mario Draghi.