U.S. Defense Secretary Lloyd Austin said Wednesday that the West must increase weapon deliveries to Ukraine and demonstrate its commitment to assisting the country’s military in fighting along a 1,000-kilometer (620-mile) front line in a grinding attrition war with Russia.

Opening a meeting on Ukraine support in Brussels, Austin urged the more than 45 nations present to show “unwavering determination to get Ukraine the capabilities that it urgently needs to defend itself.”

“We must strengthen our collective commitment to Ukraine’s self-defense, and we must work even harder to ensure that Ukraine can defend itself, its citizens, and its territory,” he said.

The meeting, which was also attended by Ukrainian Defense Minister Oleksii Reznikov, took place on the first day of a two-day NATO defense ministers meeting at the alliance’s headquarters.

Increased arms supplies cannot come soon enough for Ukrainian forces fighting to prevent Russia from seizing control of their country’s industrial east after 312 months of war.

President Volodymyr Zelenskyy pleaded Tuesday in his nightly address to the nation for more and faster deliveries of Western arms, specifically anti-missile defense systems.

Austin told the Brussels meeting that he was grateful for all of the military aid that countries had already shipped or pledged to Ukraine, but that “we can’t afford to let up and we can’t lose steam.” The stakes are simply too high.” The formal NATO meeting is scheduled to begin later Wednesday with a dinner, during which ministers will also discuss Sweden and Finland’s applications to join the trans-Atlantic military alliance.

The meeting comes less than two weeks before a NATO summit in Madrid, with Kyiv pleading with the West to send more and heavier weapons to help fend off Russia’s onslaught in eastern Ukraine.

“Allies are committed to continuing to provide Ukraine with the military equipment it requires to succeed, including heavy weapons and long-range systems,” Stoltenberg said.

He also stated that Zelenskyy would be invited to speak at the June 29-30 summit in Madrid, either in person or via videoconference.

Ukrainian Deputy Defense Minister Hanna Malyar said on Tuesday that the invaded country’s military had only received about 10% of the Western weapons it had requested “to achieve parity with the Russian army.”

“No matter how hard Ukraine works, no matter how professional our army is, we will not be able to win this war without the help of Western partners,” Malyar said during a televised news conference.

She claims that Ukraine uses 5,000 to 6,000 artillery rounds per day, while Russia uses ten times that amount.

The NATO meeting begins Wednesday evening with a working dinner where ministers will meet with counterparts from Ukraine, Georgia, Sweden, Finland, and the European Union.

“This will be an opportunity for Defense Minister Reznikov to update us on what Ukraine urgently needs. And for NATO allies to make new announcements of support to Ukraine,” Stoltenberg said.

The defense ministers meeting this week will also discuss efforts to beef up forces along NATO’s eastern flank and elsewhere, which have accelerated since Russia’s invasion of Ukraine.

“This will mean more NATO forward deployed combat formations to strengthen our battlegroups in the East, more air, sea, and cyber defenses, pre-positioned equipment and weapon stockpiles,” Stoltenberg said.

He refused to commit to a timetable for Sweden and Finland’s accession to NATO. Turkish President Recep Tayyip Erdogan has blocked the membership bids, accusing the Nordic countries of supporting Kurdish militants considered terrorists by Turkey.

“This will take some more time than we originally expected,” he said, citing Turkey’s concerns.

Erdogan made it clear on Wednesday that he will not back down.

“We will not change our stance until Sweden and Finland take clear, concrete, and determined steps in the fight against terrorism,” Erdogan said in a speech to lawmakers from his ruling party.

According to a statement from the Turkish leader’s office, he told Stoltenberg over the phone that his government wants written guarantees of a “paradigm shift” in the two countries’ anti-terrorism efforts and defense industry cooperation with Turkey.

To admit new members, all 30 NATO members must agree.

U.K. Defense Secretary Ben Wallace said at a meeting Wednesday in Oslo that the ambition for the NATO summit in Madrid is ensuring “that Sweden and Finland are successfully on the next step towards accession into NATO.”