US Secretary of State Antony Blinken on Thursday made a surprise visit to Kyiv, where he unveiled a new $2.8 billion military aid package, as President Joe Biden's administration aims to show its long-term commitment to Ukraine's defence.
The latest assistance includes a $675 million drawdown in arms, ammunition and other supplies.
Also included is $1.1bn in longer-term loans and grants for Ukraine to buy more American equipment, and an equal amount for neighbouring countries threatened by Russia.
If approved by Congress, it would bring the total military assistance for Ukraine to about $15.2bn since Mr Biden was sworn into office.
The latest tranche of aid comes at a “pivotal moment”, Mr Blinken told Ukrainian President Volodymyr Zelenskyy at the presidential palace in Kyiv.
Noting Ukraine's counter-offensive against Russia, he told Mr Zelenskyy: “The reason for this success is that this is your homeland.”
The Ukrainian leader said the economic and defensive assistance from Washington sent “crucial signals that the US stands with us”.
“For us, this is a guarantee that we can [reclaim] our lands,” he said.
On Wednesday night, Mr Zelenskyy said Ukrainian forces had taken at least two villages in the Kharkiv region, previously captured by Russia. He declined to specify which settlements.
Mr Blinken also met Ukrainian Foreign Minister Dmytro Kuleba and toured a hospital treating children who were injured in Russian strikes.
As the war approaches the seven-month mark, the Biden administration has sought to assure Ukraine of Washington's long-term support.
Mr Biden led a call with allies on Thursday about continued support for Ukraine. Other Group of Seven leaders, as well as leaders of Nato and the EU, joined the video call, the White House said.
The leaders spoke on continued security economic and security assistance for Ukraine, as well as "Russia's weaponisation of energy" and the need for sustainable and affordable energy in Europe.
Defence Secretary Lloyd Austin made a visit to Ramstein airbase in Germany to discuss continued support for Ukraine with US allies.
“Ladies and gentlemen, the face of the war is changing,” Mr Austin said.
He said Ukrainian forces have been successfully using American-supplied Himars and other rocket systems as part of their counter-offensive.
“Now, we're seeing the demonstrable success of our common efforts on the battlefield,” Mr Austin said.
The show of support from the US comes before Russian President Vladimir Putin's possible meeting with Chinese President Xi Jinping next week.
The two leaders are expected to meet on the sidelines of a summit in Uzbekistan, Russian state media reported, quoting Moscow's ambassador to Beijing.
Washington this week said that Russia had turned to North Korea to buy artillery shells and rockets, as Moscow struggles with logistics and sustainment.
Russia's ability to sustain its combat power has been heavily affected by a strain on its communication lines and supply chains, US Joint Chiefs Chairman Gen Mark Milley said.
