Reacting for the first time to his video call with Russian President Vladimir Putin this week over Kremlin aggression along the Ukrainian border, President Joe Biden said he was “very straightforward,” and that if Putin decides to invade Ukraine, he would face economic consequences “like nothing he’s ever seen.”

“There were no minced words. It was polite, but I made it very clear: If in fact, he invades Ukraine, there’ll be severe consequences,” Biden told reporters Wednesday morning as he was leaving the White House.

Tuesday’s two-hour virtual meeting between the leaders was their first known interaction since a phone call in July and Biden said, “I am absolutely confident he [Putin] got the message.”

The White House earlier said Biden warned Putin that the U.S. “would respond with strong economic and other measures in the event of military escalation,” as Russia builds up its forces on its border with Ukraine.

The president ruled out the possibility of U.S. troops going into Ukraine independently if Russia decides to invade, saying that option is “not on the table,” but left open the chance that US forces would go in with NATO allies.

“The idea of the United States is going to unilaterally use force to confront Russia invading Ukraine is not in the cards right now,” he said. “But it would depend upon what the rest of the NATO countries were willing to do as well.”

Biden said he “made it clear” to Putin that the US would “provide the defensive capability” to Ukraine and “reinforce our presence in NATO countries,” which the US already rotates relatively small contingents of American troops through Baltic countries as a symbolic measure.

Following Tuesday’s call, Biden debriefed European allies, including France’s President Emmanuel Macron, German Chancellor Angela Merkel, UK Prime Minister Boris Johnson and Italian Prime Minister Mario Draghi.

President Biden said he hopes that by Friday the US, “at least four” NATO allies and Russia will be able to announce high-level meetings to discuss Russian concerns “relative to NATO writ large” and work out accommodations “as it relates to bringing down the temperature along the Eastern Front.”

Putin also delivered his first reaction to the meeting today, saying he believes Russia’s “concerns will be heard” about NATO expansion to Ukraine. He also described the talks as “open, substantive, and constructive,” but Biden administration officials left the meeting uncertain about his next moves.

“We still do not believe that President Putin has made a decision,” national security adviser Jake Sullivan said on Wednesday. “What President Biden did today was lay out very clearly the consequences if he chooses to move.”

The White House and Kremlin officials say they would continue discussions, which could indicate a positive sign from the meeting. Biden is expected to speak with Ukraine’s President Volodymyr Zelenskyy on Thursday, according to the White House.