Local women walk along a street while Ukrainian servicemen patrol an area, as Russia's attack on Ukraine continues, in the town of Kurakhove, in Donetsk region, Ukraine May 20, 2022. Picture taken May 20, 2022.
Local women walk along a street while Ukrainian servicemen patrol an area, as Russia's attack on Ukraine continues, in the town of Kurakhove, in Donetsk region, Ukraine May 20, 2022. Picture taken May 20, 2022. Reuters / STRINGER

Russia's invasion of Ukraine was at a "pivotal" moment and the United States and its allies could not lose focus on the three-month long conflict, U.S. Defense Secretary Lloyd Austin said on Wednesday during a meeting of dozens of defense ministers in Brussels.

The meeting on the sidelines of a NATO defense ministerial will focus on weapon deliveries to Ukraine and is the third time the group of nearly 50 countries are meeting to discuss and coordinate assistance to Ukraine. The previous in-person meeting was at Ramstein Air Base in Germany in April.

Ukraine needs 1,000 howitzers, 500 tanks and 1,000 drones among other heavy weapons, presidential adviser Mykhailo Podolyak said on Monday. Western countries have promised NATO-standard weapons, including advanced U.S. rockets.

But deploying them is taking time, and Ukraine will require consistent Western support to transition to new supplies and systems as stocks dwindle of their Soviet-era weapons and munitions.

"We can't afford to let up and we can't lose steam. The stakes are too high," Austin said at the start of the meeting in Brussels.

"We must intensify our shared commitment to Ukraine's self-defense and we must push ourselves even harder to ensure that Ukraine can defend itself, its citizens, and its territory," Austin added.

Before the start of the meeting, NATO Secretary General Jens Stoltenberg said the allies would continue to supply Ukraine with heavy weapons and long-range systems and that he expected them to agree a new package of assistance to Kyiv at a NATO summit later this month.

"Sometimes these efforts take time. That's exactly why it is important to have a meeting like we have today... to meet with the Ukrainian representatives to identify the challenges and the issues they would like to raise with us when," Stoltenberg said.

'GRINDING' OPERATION

The battle for Sievierodonetsk - a city of barely more than 100,000 people before the war - is now the biggest fight in Ukraine as the conflict has shifted into a punishing war of attrition.

"Ukraine is facing a pivotal moment on the battlefield... Russia is using its long-range fires to try to overwhelm Ukrainian positions," Austin said.

U.S. officials expect announcements on additional weapons to Ukrainian forces in the coming days.

The United States has committed about $4.6 billion in security assistance to Ukraine since Russia's Feb. 24 invasion, including artillery systems such as howitzers and longer-range weapons like the High Mobility Artillery Rocket System (HIMARS).

"Russia has not given up on the fight, despite its pretty anemic progress... What we have is this grinding, slow, incremental Russian operation," said a senior U.S. defense official, speaking on the condition of anonymity.

"So the question is what do the Ukrainians need to continue the success they've already seen in slowing down and thwarting that Russian objective and that'll be a major focus for the defense ministers," the official said.

Attending the meeting in Brussels is U.S. State Department's assistant secretary for political-military affairs, Jessica Lewis, who gives policy direction for international security, defense trade and security assistance.

Lewis told Reuters in an interview on Friday that allies could ask for many defense articles to help backfill arms sent to Ukraine.

That could include tanks made by General Dynamics Corp or air defense systems from companies like Lockheed Martin or Raytheon Technologies.

Russia launched what it calls a "special operation" in Ukraine in February, saying it was needed to rid the country of dangerous nationalists and degrade Ukraine's military capabilities - aims the West denounced as a baseless pretext.

The Biden administration has said it has received assurances from Kyiv that those longer-range weapons will not be used to attack Russian territory, fearing an escalation of the conflict.

Kyiv has said it is losing 100 to 200 soldiers each day, with hundreds more wounded. In an overnight address, President Volodymyr Zelenskiy described the battle for the eastern Donbas region - partly occupied by Moscow proxies since 2014 - as one of the most brutal in European history.