Spanish Prime Minister Pedro Sanchez arrived in Kyiv on Saturday to signal EU support for Ukraine as the country's commander-in-chief said he was frustrated by the slow deliveries of Western weapons.
Sixteen months into Russia's invasion, Kyiv says it is fighting "fierce" battles as part of its counteroffensive launched last month after weeks of anticipation.
His visit also comes ahead of a key NATO summit in Vilnius later this month that is expected to map out the future relationship between Ukraine and the Western military bloc.
"In Kyiv already. I wanted the first act of the Spanish presidency of the council of the European Union to be in Ukraine" with its president, Sanchez wrote on his official Twitter account, saying he would convey "all of Europe's solidarity".
"We will keep supporting the Ukrainian people until peace returns to Europe," added Sanchez, who announced the visit during an EU summit on Thursday, saying the aim was to demonstrate the EU's "unfaltering support" for Kyiv.
Ukraine received EU candidacy status a year ago and is hoping to begin formal negotiations this year on what it needs to do to firm up its membership bid.
Kyiv also said this week that the time had come for NATO to clarify its stance on Ukraine's membership.
'Pisses me off'
But Ukraine's military commander-in-chief Valery Zaluzhny said in an interview published Friday that his country's counteroffensive plans have been hobbled by the lack of adequate firepower, from modern fighter jets to artillery ammunition.
Zaluzhny told The Washington Post he is frustrated by the slow deliveries of promised weaponry from the West.
It "pisses me off" that some in the West complain about the slow start and progress to the long-awaited push against Russian occupying forces in the country's south, he said.
Zaluzhny said his Western supporters would not themselves launch an offensive without air superiority, but Ukraine is still awaiting F-16 fighters promised by its allies.
"I do not need 120 planes. I'm not going to threaten the whole world. A very limited number would be enough," he told the newspaper.
He also complained he has a fraction of the artillery shells that Russia is firing, The Washington Post reported.
Zaluzhny said he is in constant contact with Western partners, like Pentagon Joint Chiefs Chairman General Mark Milley, who are keenly aware of his needs.
But Milley alone can't make the decision, and the delays are deadly, Zaluzhny said.
"It's just that while that decision is being made, in the obvious situation, a lot of people die every day -- a lot. Just because no decision has been made yet."
"It's not a show the whole world is watching and betting on or anything. Every day, every meter is given by blood," he said.
'A little slow'
Speaking later Friday in Washington, Milley said the United States and allies were working hard to supply Ukraine.
"We are giving them as much help as humanly possible," he said.
Milley said the United States was still in talks on providing Ukraine with F-16s and ATACMS, precision missiles that could more than double the range Ukraine forces are able to target.
He acknowledged that some people had expressed impatience with the pace of the counteroffensive.
"Sure, it goes a little slow but that is part of the nature of war," he said.
Separately, a US official confirmed to AFP on Friday that CIA Director William Burns recently traveled to Ukraine where he met with intelligence counterparts and Zelensky. During his trip Burns reaffirmed "the US commitment to sharing intelligence to help Ukraine defend against Russian aggression," the US official said.