US ready to 'respond decisively' to Russian attack on Ukraine: Biden

US President Joe Biden on Tuesday (local time) said that Washington is ready to respond decisively to the Russian attack on Ukraine.

"We are ready to respond decisively to the Russian attack on Ukraine which is still very much a possibility," Biden said in remarks at the White House.

President Biden acknowledged reports on Tuesday that Russia has ordered the partial withdrawal of its troops near Ukraine's borders, but stressed that the US has "not yet verified" the Kremlin's claims and that an invasion remains "distinctly possible."

"We have not yet verified the Russian military units are returning to their home bases -- indeed, our analysts indicate that they remain very much in a threatening position, and the fact remains right now Russia has more than 150,000 troops circling Ukraine and Belarus, and along Ukraine's border and invasion remains distinctly possible."

"We are not seeking direct confrontation with Russia though I have been clear if Russia targets Americans in Ukraine, we will respond forcefully," the US President asserted.

In remarks televised nationally, Biden emphasized that the path to diplomacy and de-escalation remains open but said if Russia invades Ukraine in the coming days or weeks "it will be met with overwhelming international condemnation."

"Accountability matters. If Russia does invade in the days and weeks ahead, the human cost for Ukraine will be immense. And the strategic cost for Russia will also be immense. If Russia attacks Ukraine, it will be met with overwhelming international condemnation. The world will not forget that Russia chose needless death and destruction," the US President said in White House remarks.

Biden's speech came hours after Russian President Vladimir Putin said Moscow's security concerns should be addressed and taken seriously.

Biden told reporters if Russia invaded Ukraine there would be crippling sanctions that could impact the American economy, that could suffer from disruption to energy supply and price hikes in the likely event that sanctions were levied on Russia in response to any invasion of Ukraine.

"If Russia decides to invade that will also have consequences here at home, Biden said in remarks at the White House.

"The American people understand that defending democracy and liberty is never without cost."

He said the US was prepared to respond to other attempts at inflicting pain on Americans, including in cyberspace.

"We are not seeking direct confrontation with Russia, though I have been clear that if Russia targets Americans in Ukraine, we will respond forcefully. If Russia attacks the United States or allies through asymmetric means, like disruptive cyberattacks against our companies or critical infrastructure, we're prepared to respond," Biden said.

Amid the ongoing tensions that started in November at the Ukraine-Russia border, President Biden made it clear that the United States is not seeking to add to the volatility.

"Let me be equally clear about what we are not doing: The United States and NATO are not a threat to Russia," said Biden, speaking from the White House.

"Ukraine is not threatening Russia. Neither the US nor NATO have missiles in Ukraine. We do not, do not have plans to put them there as well. We're not targeting the people of Russia. We do not seek to destabilize Russia. To the citizens of Russia: you are not our enemy. I do not believe you want a bloody, destructive war against Ukraine," he said.

Noting that Russia and the United States teamed up in World War II -- which he called "a war of necessity" -- Biden drew a distinction between the current state of affairs.

"If Russia attacks Ukraine, it will be a war of choice, or a war without cause or reason. I say these things not to provoke, but to speak the truth, because the truth matters. Accountability matters," Biden said.

"If Russia does invade in the days and weeks ahead, the human cost for Ukraine will be immense," he added.

Diplomatic efforts continued Tuesday between US and Russia. US Secretary of State Antony Blinken held a call with Lavrov, according to a State Department. Biden spoke with French President Emmanuel Macron on Tuesday about the evolving crisis.