HIROSHIMA, Japan (AP) – Ukrainian President Volodymyr Zelenskyy huddled with some of his biggest backers as the Group of Seven summit closed in Hiroshima on Sunday, building momentum for his country’s war effort even as Russia claimed a battlefield victory that was quickly disputed by Ukraine.

The Ukrainian leader’s in-person appearance in his trademark olive drab underscored the centrality of the war for the G7 bloc of rich democracies. It also stole much of the limelight from other priorities, including security challenges in Asia and outreach to the developing world, that the leaders focused on at the three-day gathering.

Hosting Japanese Prime Minister Fumio Kishida said the group was committed to “strong backing for Ukraine from every possible dimension.”

Mr. Zelenskyy held two major rounds of meetings Sunday, one with G7 leaders and a second with them and a host of invited guests including India and South Korea. He also spoke one-on-one with several leaders.

Hanging over Sunday’s talks was the Russian claim that forces of the Wagner private army and Russian troops had seized the Ukrainian city of Bakhmut. The eight-month battle for the eastern city—seen by both sides as a major symbolic prize—has been the longest and likely bloodiest of the war.

Comments by Mr. Zelenskyy earlier in the day in English suggested that the Russians had finally taken the city. But he and other Ukrainian officials later cast doubt on that assessment, with Mr. Zelenskyy telling reporters in Ukrainian that “Bakhmut is not occupied by the Russian Federation as of today.”

U.S. President Joe Biden announced new military aid worth $375 million for Ukraine, saying America would provide ammunition and armored vehicles. That pledge came after the U.S. agreed to allow training on American-made F-16 fighter jets, laying the groundwork for their eventual transfer to Ukraine.

“We have Ukraine’s back and we’re not going anywhere,” Mr. Biden said.

Even before Mr. Zelenskyy landed Saturday, the G7 nations had unveiled a slew of new sanctions and other measures meant to punish Moscow over its invasion that began in February last year.

While Ukraine dominated the summit, the leaders of Japan, the U.S., the United Kingdom, France, Germany, Canada and Italy, as well as the European Union, also aimed to address global worries over climate change, poverty, economic instability and nuclear proliferation.

And Mr. Biden sought to reassure world leaders that the U.S. would not default because of the debt limit standoff that has cast a large shadow over his trip.

Two U.S. allies—South Korea and Japan—furthered efforts to improve ties colored by lingering anger over issues linked to Japan’s brutal 1910-1945 colonization of the Korean Peninsula. Mr. Kishida and South Korean President Yoon Suk Yeol visited a memorial to Korean victims, many of them slave laborers, of the August 6, 1945, atomic bombing.

Washington wants the two neighbors, both of which are liberal democracies and bulwarks of U.S. power in the region, to stand together on issues ranging from Russia to North Korea.

Mr. Biden, Mr. Yoon and Mr. Kishida met briefly as a group outside the summit venue in front of Hiroshima Bay. Mr. Biden invited the two leaders to visit Washington for a trilateral meeting and they accepted, said a U.S. official who briefed reporters on condition of anonymity.

In a meeting with Mr. Zelenskyy, Mr. Yoon promised to provide South Korean demining equipment and ambulances to Ukraine.

Mr. Zelenskyy also met on the sidelines of the summit with Indian Prime Minister Narendra Modi, their first face-to-face talks since the war. He briefed him on Ukraine’s peace plan, which calls for the withdrawal of Russian troops from the country before any negotiations.

India, the world’s largest democracy and a major buyer of Russian arms and oil, has avoided outright condemnation of Russia’s invasion.

“Zelenskyy’s presence puts some pressure on G7 leaders to deliver more—or explain to him directly why they can’t,” said Matthew Goodman, an economics expert at the Center for Strategic and International Studies think tank in Washington.

The G7 has vowed to intensify pressure on Russia, calling its assault on Ukraine “a threat to the whole world in breach of fundamental norms, rules and principles of the international community.”

The Russian Foreign Ministry on Sunday denounced the G7 as “fixated on comprehensive confrontation with Russia...The leaders of the G7 countries brought to their meeting the chief of the Kyiv regime, who is controlled by them, and ultimately turned the Hiroshima event into a propaganda show.”

The group took a different approach in its comments on China, the world’s No. 2 economy. The leaders said they did not want to harm China and were seeking “constructive and stable relations” with Beijing.

They also urged China to pressure Russia to end the war in Ukraine and “support a comprehensive, just and lasting peace.”

“We’re not looking to decouple from China, we’re looking to de-risk and diversify,” Mr. Biden said.

He also vowed to help Taiwan defend itself against a potential attack by China, saying that there is an understanding by the U.S. and its allies that “if China were to act unilaterally, there would be a response.”

China’s Foreign Ministry for its part urged G7 members to “focus on addressing the various issues they have at home, stop ganging up to form exclusive blocs, stop containing and bludgeoning other countries.”

The G7 also warned North Korea, which has been testing missiles at a torrid pace, to completely abandon its nuclear weapon ambitions, “including any further nuclear tests or launches that use ballistic missile technology.”

The G7 leaders have rolled out a new wave of global sanctions on Russia, now the most-sanctioned country in the world, as well as plans to enhance the effectiveness of existing financial penalties meant to constrain President Vladimir Putin’s war effort.

The latest sanctions aimed at Russia include tighter restrictions on already-sanctioned people and firms involved in the war effort. More than 125 individuals and organizations across 20 countries have been hit with U.S. sanctions.

Russia had participated in some summits with the other seven countries before being removed from the then-Group of Eight after its 2014 annexation of Crimea.

Mr. Kishida, mindful of the host city’s symbolic importance, has twice taken leaders to visit to a peace park dedicated to the tens of thousands who died in the world’s first wartime atomic bomb detonation. He had wanted nuclear disarmament to be a major focus of discussions.

Some survivors of the 1945 atomic bomb attack and their families worried that Mr. Zelenskyy’s inclusion at the summit overshadowed that priority. Etsuko Nakatani, an activist whose parents survived the Hiroshima atomic bombing, said the leaders’ visit was “not appropriate for Hiroshima, which is a peace-loving city.”

Protesters carrying “No War No G7” banners briefly scuffled with riot police deployed as part of a massive show of force throughout the city during a march Sunday.

The G7 leaders also discussed efforts to strengthen the global economy and address rising prices that are squeezing families and government budgets around the world, particularly in developing countries in Africa, Asia and Latin America. They reiterated their aim to pull together up to $600 billion in financing in a program meant to offer countries an alternative to China’s investment dollars.