WASHINGTON, Dec 6 (Reuters) - U.S. President Joe Biden will warn Russian President Vladimir Putin of severe economic consequences should Russia go ahead with an invasion of Ukraine, a senior U.S. administration official said on Monday. Biden and Putin are to hold a video call on Tuesday as the United States tries to head off Russia from launching military action against Ukraine after Moscow massed tens of thousands of troops on the Ukraine border. The official, briefing reporters ahead of the call, said the United States has been working with European allies about a strong response should an invasion go forward. He said the United States and Europe would impose severe economic pain. Biden planned to consult European allies later in the day to stress the need for solidarity, he said. "We believe there is a way forward to allow us to send a clear message to Russia that there will be enduring and meaningful costs" should an invasion take place, the official said. Russia has dismissed U.S. media reports about a possible Russian attack on Ukraine, accusing Washington of trying to aggravate the situation while blaming Moscow. U.S. Secretary of State Antony Blinken planned a call on Monday with Ukraine President Volodymyr Zelenskiy and Biden planned to talk to him in the days after the call, the official said. Russia has a potential diplomatic off-ramp through the Minsk agreement if it wishes, the official said. This is a previously negotiated agreement aimed at ending war in the Donbas region of Ukraine. "We"re encouraging Russia to return to dialogue through diplomatic avenues," the official said. The official would not detail the economic sanctions that are ready to be imposed. A source familiar with the situation said targeting Putin"s inner circle with sanctions had been discussed but no decision had been made. CNN reported the United States could include the extreme step of disconnecting Russia from the SWIFT international payment system used by banks around the world. The White House declined comment. More than 94,000 Russian troops are believed to be massed near Ukraine"s borders. Ukraine Defense Minister Oleksii Reznikov said on Friday that Moscow may be planning a large-scale military offensive at the end of January, citing intelligence reports. The U.S. official said it was still unclear whether Putin had made a final decision to launch an invasion. The United States does not seek conflict with Russia but when necessary will impose meaningful consequences for harmful actions, the official added. Russia has said it can move troops around on Russian territory as it sees fit and that they pose no external threat. Ukraine"s ties with Russia collapsed in 2014 after Moscow-backed forces seized territory in eastern Ukraine that Kyiv wants back. Kyiv says some 14,000 people have been killed in fighting since then. Since the latest crisis started, Moscow has set out demands for legally binding security guarantees from the West that NATO will not admit Ukraine as a member or deploy missile systems there to target Russia.