President Biden ruled out the possibility of sending U.S. troops to Ukraine amid the Russian military buildup on the country's border but did warn that he would impose severe sanctions if Russia invaded its neighbor.

"That is not on the table," Biden said when asked by reporters Wednesday if the U.S. would be sending troops to Ukraine. "We have a moral obligation and a legal obligation to our NATO allies if they were to attack under Article 5, that's a sacred obligation. That obligation does not extend to ... Ukraine."

President Joe Biden (REUTERS/Evelyn Hockstein)

Biden's comments come after he had a two-hour phone call with Russian President Vladimir Putin Tuesday, with officials saying the call between the two leaders grew tense with 70,000 troops along the Russia-Ukraine border.

He also said hopes for meetings about Putin's concerns over Ukraine joining NATO.

"We hope by Friday we'll be able to say, to announce to you that we're having meetings at a higher level, not just with us but with at least four major NATO allies and Russia, to discuss the future of Russia's concerns relative to NATO writ large and whether or not we can work out any accommodations when it comes to bringing down the temperature along the eastern front," Biden said.

US GOING TO WAR WITH RUSSIA OVER UKRAINE WOULD 'COURT DESTRUCTION OF THE KNOWN WORLD': MACGREGOR

But the president did say he made clear to Putin that the U.S. would impose severe sanctions on Russia should it invade Ukraine, noting that such sanctions would have "severe" economic consequences.

"I was very straightforward. There were no minced words. I was polite, but I made it very clear: If, in fact, he invades Ukraine, there will be severe consequences. Severe consequences. Economic consequences like none he's ever seen or ever have been seen, in terms of being imposed," Biden said.

Biden said Putin clearly received the message.

"He knows. His immediate response was he understood that," Biden said.

White House officials said Biden's phone call with Putin ended without the president gaining any clarity on whether the Russian leader had made up his mind to launch an attack, though both leaders spoke Wednesday about the possibility of opening up new diplomatic channels in an effort to avoid the outbreak of war.

Putin has argued that the presence of NATO troops near the Russian border threatens its national security, a situation made worse by Ukraine's potential future membership in the defense bloc.

Russian President Vladimir Putin (AP Photo/Alexander Zemlianichenko, Pool)

Ukraine has been attempting to gain membership into NATO for several years. Biden has said the country would have to do more to curb corruption in order to enter the final stages of gaining membership.

That didn't stop Putin from asking for legally binding language in Tuesday's call that would prevent Ukraine from joining NATO, something Biden refused to agree to while assuring the Russian leader that NATO would hear out his concerns in high-level talks.

CLICK HERE TO GET THE FOX NEWS APP

President Joe Biden and Russian President Vladimir Putin (AP Photo/Patrick Semansky, File)

Putin himself held a press conference Wednesday to address his talks with Biden, saying he was optimistic that the two sides could continue to have constructive dialogue.

"We agreed that an appropriate structure will be created that will be able to professionally deal with this," Putin said.

"The conversation was very open, substantive and constructive. I hope that this is how the American side assesses the results as well," he added. "We have the opportunity to continue the dialogue, and I think this is the most important thing."