Tomas Kopecny, the Czech government envoy for Ukraine reconstruction, told reporters that Ukraine, battling a Russian invasion since February 2022, could get millions of shells if allies managed to collect the money.

"The first delivery under the umbrella of this Czech initiative will be in June, and it will be dozens of thousands of shells, between 50 and 100," he said on the fringes of a meeting of NATO foreign ministers in Prague.

Ukrainian forces said earlier this year they were so low on supplies that they were forced to ration ammunition, letting Russia seize ground.

Russia has more recently launched a widescale offensive in northeastern Ukraine ahead of the delivery of US weapons that were approved after a long delay in Congress.

Besides the Czech Republic, Canada, Denmark, Germany, the Netherlands and Portugal have so far contributed some 1.7 billion euros ($1.8 billion) to buy 500,000 shells in the first phase, Kopecny said.

Ten other countries are "in the process" with talks for donations under way, he said.

In Prague for the NATO meeting, US Secretary of State Antony Blinken hailed the so-called Czech initiative, estimating that the effort will bring one million shells to Ukraine by the end of the year.

"Czechia's leadership is really quite extraordinary," Blinken said. "We're not only stronger, we're more likely to prevent -- to deter -- aggression when we're united."

Kopecny urged further contributions as Ukraine will need 200,000 shells a month in the next two years "just to make the balance" vis-a-vis Russia.

The necessary supplies will swallow "between seven and ten billion euros per year," he said, adding the 500,000 shells obtained or pledged so far would suffice for two and a half months.

He said allies were competing for millions of rounds of ammunition produced outside Europe with Russia.

"It's about speed," he said. "It's a market where the owner of a product wants to sell it at the highest price."

Kopecny also slammed allies for a failure to use bank loans to finance the weapon supplies to Ukraine.

"It's so frustrating when you compare it with the expenses and the loans the EU took for Covid. Hundreds of billions of euros. Easy. And here we're struggling with hundreds of millions."