US Secretary of State Antony Blinken arrived in Kyiv as America has announced a further package of almost $2.7bn (£2.4bn) military aid for Ukraine.
The announcement was made by the US defence secretary Lloyd Austin at a US air base in Ramstein, Germany. Weapons include howitzers, munitions, Humvee vehicles and anti-tank systems.
It comes on top of a previous $13bn (£11.3bn) in military aid for Ukraine previously announced by Washington.
The announcement was also made as Ukraine pressed a counter-offensive against Russia in the south, east and north of the country.
“This is a very important signal that the United States is with us. For us this is a guarantee that we can return our territories and our land,” Volodymyr Zelensky said in video comments.
Mr Blinken met the Ukrainian leader at his fortified presidential administration building in Kyiv, and said his visit came at a “pivotal moment” for Ukraine, noting the counteroffensive was proving effective.
“I think the reason for this success is that this is your homeland, not Russia’s,” he told Mr Zelensky.
Earlier, President Zelensky had hailed his forces’ military gains, saying the whole country feels “proud” of its “warriors”.
In a late night address on Wednesday, the Ukrainian president said he had received “good news” regarding his soldiers’ counteroffensive against Russia in the northeastern Kharkiv region.
Although he did not name the places that the Ukrainian army had recaptured, he thanked the brigades there for their bravery.
“I think every citizen feels proud of our warriors. It is a well-deserved pride, a right feeling,” Mr Zelensky said.
“Each success of our military in one direction or another changes the general situation along the entire frontline in favour of Ukraine.”
Mr Zelensky added that every loss inflicted on Russia helped Ukraine in its defence of other parts of its territory, including the eastern Donbas region.
Oleksiy Arestovych, one of the president’s advisers, also spoke of Ukraine’s successes near Kharkiv, noting that its advances could lead to Russian troops being encircled.
The speed of the Ukrainian counterattack in the northeast appears to have taken Moscow by surprise.
Using “tactical surprise” to their advantage, Ukrainian forces advanced 20km (12 miles) into Russian-occupied territory on Wednesday, according to the Institute for the Study of War (ISW).
This resulted in the recapture of almost 400 square kilometres (154 square miles) of land, also according to the ISW.
The US think tank also said that Kyiv’s counterattack in the south near the Russian-controlled city of Kherson is paying dividends. It is likely that Ukraine’s Kharkiv offensive is being helped by the reallocation of Russian soldiers to the southern front, the ISW explained.
“Ukrainian forces in southeastern Kharkiv oblast are likely exploiting Russian force reallocation to the southern axis to conduct an opportunistic yet highly effective counteroffensive northwest of Izyum,” it said.
In its latest military update on Vladimir Putin’s war, the Ministry of Defence (MoD) said Ukraine was successfully targeting Russian river crossings near Kherson.
“Ukraine has probably destroyed a military pontoon bridge at Darivka, which Russian forces had deployed after the nearby road bridge was severely damaged,” the MoD said, adding that such operations slowed the Kremlin’s ability to deploy extra soldiers and resources from the east.
Mr Blinken also met with Ukrainian foreign minister Dmytro Kuleba in Kyiv.
The senior American official will announce a new $2bn (£1.74bn) fund to help Ukraine and other countries’ militaries. Roughly half of the total will be given to Kyiv, a US state department office said.
Mr Blinken’s trip followed US president Joe Biden’s approval of a separate $675m (£587m) weapons package. Washington will send more ammunitions, Humvees and anti-tank systems, officials said.
