Washington, 7 December 2021 (dpa/MIA) - US President Joe Biden warned his Russian counterpart Vladimir Putin of economic consequences in the event of an escalation in the conflict with Ukraine during their video summit on Tuesday. The White House said after the conversation that Biden expressed "deep concerns of the United States and [its] European allies about Russia's escalation of forces surrounding Ukraine." The summit, which focused on tensions over the Ukraine conflict, started shortly after 1500 GMT. It was scheduled to run for several hours, but ended after only about two hours. The Kremlin had previously stated that it could become a very long conversation in view of the multitude of conflict topics. Biden told Putin it was good to see him again, and lamented the fact that the Russian leader had not been at the G20 summit in Rome in late October. Next time he would like to meet Putin in person again, Biden said. Biden made it clear that the United States and its allies "would respond with strong economic and other measures in the event of military escalation" in Ukraine. The US president reiterated his support for Ukraine’s "sovereignty and territorial integrity" and called for de-escalation and a return to diplomacy, according to the White House. For weeks, the US has been accusing Russia of deploying troops not far from the border with Ukraine. The West fears a Russian invasion of the former Soviet republic. Russia rejects this and accuses Ukraine of having moved more than 120,000 soldiers to the front line with the separatist regions. No "breakthroughs" were expected from the summit, Kremlin spokesman Dmitry Peskov stressed. He called the meeting a working discussion at a very difficult time. Biden now plans to consult with his European allies following the talks with Putin, the White House said. The US president is due to speak with outgoing German Chancellor Angela Merkel, French President Emmanuel Macron, British Prime Minister Boris Johnson and Italian Prime Minister Mario Draghi after his conversation with Putin, the statement said. During talks the previous day, the allies agreed to stay in close contact to develop a coordinated and comprehensive response to Russia's military build-up on Ukraine's borders. European Commission President Ursula von der Leyen also warned Moscow of further sanctions. Existing sanctions could be expanded or new punitive measures taken, she said. At the moment, von der Leyen said, it was Russia's deliberate decisions and aggressive actions that were further destabilizing Europe's security. According to the Kremlin, the two heads of state connected via a specially protected and tap-proof line. The talks were also supposed to deal with possible mutual security guarantees between Russia and NATO. As heads of state, Putin and Biden had first met in person in Geneva in June. The video summit on Tuesday had also been expected to deal with the cybersecurity of both countries as well as Iran's nuclear programme and other international conflicts.