WASHINGTON: The United States and its allies will impose "severe sanctions" on Russia after its military forces launched an attack on Ukraine, US President Joe Biden said after blasts were heard in the Ukrainian capital of Kyiv and other cities.
Biden said he spoke with Ukrainian President Volodymyr Zelenskiy and briefed him on the steps Washington was taking to rally international condemnation of Russia, including at a special meeting of the United Nations Security Council.
"Tomorrow, I will be meeting with the leaders of the G7, and the United States and our allies and partners will be imposing severe sanctions on Russia," Biden said in a statement.
Washington would continue to provide support and assistance to Ukraine and its people, he added, but gave no details.
Earlier, Biden said his prayers were with the people of Ukraine "as they suffer an unprovoked and unjustified attack by Russian military forces".
"President Putin has chosen a premeditated war that will bring a catastrophic loss of life and human suffering," Biden said in a statement late on Wednesday.
"Russia alone is responsible for the death and destruction this attack will bring. The world will hold Russia accountable."
Biden said he would monitor the situation from the White House before meeting online with his counterparts from the Group of Seven advanced economies early on Thursday.
Then, he said, he would "speak to the American people to announce the further consequences the United States and our allies and partners will impose on Russia for this needless act of aggression against Ukraine and global peace and security."
Biden said Washington would also coordinate with NATO allies "to ensure a strong, united response that deters any aggression against the alliance."
Other world leaders also condemned the move.
German Chancellor Olaf Scholz described the military operation as "a glaring violation" of international law on a "dark day" for Europe.
"Germany condemns in the strongest possible terms this unscrupulous act by President Putin. Our solidarity goes out to Ukraine and its people," he added in a statement.
NATO chief Jens Stoltenberg denounced Russia's "reckless and unprovoked attack" on Ukraine, warning it put "countless" lives in jeopardy.
"I strongly condemn Russia's reckless and unprovoked attack on Ukraine, which puts at risk countless civilian lives. Once again, despite our repeated warnings and tireless efforts to engage in diplomacy, Russia has chosen the path of aggression against a sovereign and independent country," Stoltenberg said in a statement.
"NATO Allies will meet to address the consequences of Russia's aggressive actions. We stand with the people of Ukraine at this terrible time. NATO will do all it takes to protect and defend all allies."
Canadian Prime Minister Justin Trudeau said the country condemns the attack "in the strongest possible terms".
Putin announced a "military operation" in Ukraine on Thursday and called on soldiers there to lay down their arms, defying Western outrage and global appeals not to launch a war.
Putin made a surprise statement on television to declare his intentions.
"I have made the decision of a military operation," he said shortly before 0300 GMT in Moscow, as he vowed retaliation against anyone who interfered.
He also called on the Ukraine military to lay down its arms.
An AFP reporter in Kyiv, Ukraine's capital, heard explosions within about 30 minutes of Putin's announcement. Explosions were also heard in the eastern city of Mariupol and the Black Sea port of Odessa, according to AFP reporters.
Russia has demanded an end to NATO's eastward expansion and Putin repeated his position that Ukrainian membership of the US-led Atlantic military alliance was unacceptable.
He said he had authorised military action after Russia had been left with no choice but to defend itself against what he said were threats emanating from modern Ukraine, a democratic state of 44 million people.
"Russia cannot feel safe, develop, and exist with a constant threat emanating from the territory of modern Ukraine," Putin said. "All responsibility for bloodshed will be on the conscience of the ruling regime in Ukraine."
The full scope of the Russian military operation was not immediately clear but Putin said: "Our plans do not include the occupation of Ukrainian territories. We are not going to impose anything by force."
Ukrainian President Volodymyr Zelenskiy said Russia had carried out missile strikes on Ukrainian infrastructure and border guards, and that explosions had been heard in many cities.