US President Joe Biden warned "this could be a long and difficult battle" after announcing an additional $800 million in security aid for Ukraine.
"The American people will be steadfast in our support [to] the people of Ukraine in the face of Putin's immoral, unethical attacks on civilian populations. We are united in our abhorrence of Putin's depraved onslaught, and we're going to continue to have their backs as they fight for their freedom, their democracy, their very survival," he said in remarks from the White House.
"We're going to give Ukraine the arms to fight and defend themselves through all the difficult days ahead. We're going to continue to mobilize humanitarian relief to support people within Ukraine and those forced to flee Ukraine," Biden said.
He also pledged to keep up sanctions on Russia.
"We will support Ukraine's economy with direct financial assistance. Together with our allies and partners, we will keep up the pressure in Putin's crumbling economy, isolating him on the global stage. That's our goal. Make Putin pay the price, weaken his position while strengthening the hand of the Ukrainians on the battlefield and at the negotiating table," he said.