In a video call that lasted for just over two hours on Tuesday, President Biden warned Russian President Vladimir Putin that if Russia invades Ukraine the U.S. will impose unprecedented sanctions and provide additional weaponry to the Ukrainians, national security adviser Jake Sullivan said.

Why it matters: Russia's military activity on the border with Ukraine has triggered alarms from the U.S. and its European allies of a potential large-scale Russian invasion in early 2022. Sullivan said Biden made clear to Putin that, "things we did not do in 2014, we are prepared to do now."

• "There was a lot of give and take, there was no finger wagging, but the president was crystal clear about where the United States stands on these issues," Sullivan said of a call that the Kremlin also described as "businesslike."
• "We still do not believe that President Putin has made a decision, what President Biden did today was lay out very clearly the consequences if he chooses to move. He also laid out an alternative path," Sullivan said, noting that Biden and NATO were willing to discuss European security with the Russians.
• Sullivan did not provide details on the sanctions the U.S. was prepared to impose, or the defensive weaponry that would be provided to the Ukrainians.

Driving the news: Biden held talks with the leaders of France, Germany, Italy and the U.K. both before and after the call, and will speak with Ukrainian President Volodymyr Zelensky on Thursday, Sullivan said.

• Leading up to the call, the U.S. and its European allies discussed potential sanctions that would exceed the measures they imposed after Russia annexed Crimea from Ukraine in 2014.
• Biden officials also said the U.S. is prepared to send additional military aid to Ukraine and increase its troop presence, capabilities and military exercises on NATO's "eastern flank" in response to any Russian incursion.
• Soon after the call ended, Congress released the text of an annual defense bill that includes $300 million in security assistance to Ukraine — $50 million more than what Biden had requested in his initial budget proposal.

The other side: Putin has blamed Ukraine's pro-Western government and NATO for escalating tensions with Russia.

• In the call, he sought legal guarantees from Biden that NATO would not expand to the East or deploy offensive missile systems on Ukrainian soil, according to the Kremlin readout.

The big picture: Russia has deployed some 94,000 troops to various points near the border, and is "stepping up its planning for significant military action against Ukraine," a senior official told reporters on Monday ahead of the Biden-Putin conversation.

• The White House has also warned that the Kremlin is waging a disinformation campaign against Ukraine, potentially as a pretext to blame Kyiv for any military clash.
• "We do not know whether President Putin has made a decision about further military escalation in Ukraine. But we do know that he is putting in place the capacity to engage in such escalation should he decide to do so," the official said.

In addition to Ukraine, the White House said Biden and Putin discussed the "strategic stability" dialogue between the U.S. and Russia, ransomware attacks and the Iran nuclear negotiations.