HIROSHIMA, Japan >> President Joe Biden told allies today he was approving plans to train Ukrainian pilots on U.S.-made F-16 fighter jets, according to two people familiar with the matter, as leaders of the world’s most powerful democracies worked to toughen punishments on Russia for its 15-month invasion of Ukraine.

The Group of Seven leaders are meeting in Hiroshima, with Ukrainian President Volodymyr Zelenskyy set to take part in their summit on Sunday.

The green light on F-16 training is the latest shift by the Biden administration as it moves to arm Ukraine with more advanced and lethal weaponry, following earlier decisions to send rocket launcher systems and Abrams tanks. The U.S. has insisted that it is sending weapons to Ukraine to defend itself and has discouraged attacks by Ukraine into Russian territory.

The G7 leaders also used their summit to roll out a new wave of global sanctions on Moscow as well as plans to enhance the effectiveness of existing financial penalties meant to constrain President Vladimir Putin’s war effort.

“Our support for Ukraine will not waver,” the G7 leaders said in a statement released after closed-door meetings. They vowed “to stand together against Russia’s illegal, unjustifiable and unprovoked war of aggression against Ukraine.”

“Russia started this war and can end this war,” they said.

Zelenskyy has consistently called for the supply of Western fighter jets to bolster his country’s defenses against Russia’s invasion, but has until now faced skepticism from the U.S. that they would turn the tide in the war.

Now, as Ukraine has improved its air defenses with a host of Western-supplied anti-aircraft systems and prepares to launch a counteroffensive against Russia, officials believe the jets could become useful in the battle and essential to the country’s long-term security.

Biden’s backing of training Ukrainian pilots on advanced fighter jets serves as a precursor to sending the jets to Ukraine for the first time. But decisions on when, how many, and who will provide the fourth-generation fighter jets will be made in the months ahead while the training is underway, Biden told leaders.

The F-16 training is to be conducted in Europe and will likely begin in the coming weeks. That’s according to two people who spoke on the condition of anonymity to discuss Biden’s private conversations with allies.

Oleksiy Danilov, secretary of Ukraine’s National Security and Defense Council, said on national television that Zelenskyy would attend the summit.

“There will be very important matters decided there, so physical presence is a crucial thing to defend our interests,” Danilov said today.

The Council later walked back those remarks, saying in a statement that Zelenskyy would be joining the G7 summit in Hiroshima via video link. The resident’s office would not confirm either way for security reasons, and his exact travel plans were not clear.

Zelenskyy announced today that he had also opened a visit to Saudi Arabia, where Arab leaders were holding their own summit.

European allies in recent weeks have warmed to the notion of sending fighter jets to Ukraine, as have elements of Biden’s Cabinet, including Secretary of State Antony Blinken, who has emerged as a staunch advocate within the administration. Under export licensing rules, the U.S. needed to sign off on any allied effort to train Ukrainian pilots or to provide them with the jets.

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. The financial penalties have been primarily focused on sanctions evaders connected to technology procurement for the Kremlin. The Commerce Department also added 71 firms to its own list.

Treasury Secretary Janet Yellen said the today sanctions “will further tighten the vise on Putin’s ability to wage his barbaric invasion and will advance our global efforts to cut off Russian attempts to evade sanctions.”

In addition, new reporting requirements were issued for people and firms that have any interest in Russian Central Bank assets. The purpose is to “fully map holdings of Russia’s sovereign assets that will remain immobilized in G7 jurisdictions until Russia pays for the damage it has caused to Ukraine,” the U.S. Treasury Department said.

Russia is now the most-sanctioned country in the world, but there are questions about the effectiveness.

Maria Snegovaya, a senior fellow at the Center for Strategic and International Studies, said going into the summit that while G7 countries “deserve credit” for their sanctions, “Russia still maintains capacity to fight this war in the long term.”

She added that war’s costs are “easily manageable for Russia in the next couple of years at least, and the cumulative effect of sanctions is just not strong enough to radically alter that.”

The G7 nations said in today’s statement that they would work to keep Russia from using the international financial system to prosecute its war, and they urged other nations to stop providing Russia with support and weapons “or face severe costs.”

The European Union was focused on closing loopholes and plans to restrict trade in Russian diamonds, Charles Michel, president of the European Council, told reporters today.

Putin’s nuclear threats against Ukraine, along with North Korea ‘s months-long barrage of missile tests and China’s rapidly expanding nuclear arsenal, have resonated with Japan’s push to make nuclear disarmament a major part of the G7 summit. World leaders today visited a peace park dedicated to the tens of thousands who died in the world’s first wartime atomic bomb detonation.

Japanese Prime Minister Fumio Kishida, who represents Hiroshima in parliament, wants nuclear disarmament to be a major focus of discussions, and he formally started the summit at Hiroshima’s Peace Memorial Park.

The visit by world leaders was to a park dedicated to preserving reminders of Aug. 6, 1945, when a U.S. B-29 dropped an atomic bomb over Hiroshima, and the city has become synonymous with anti-nuclear peace efforts.

Biden, who scrapped plans to travel on to Papua New Guinea and Australia after his stay in Japan so that he can get back to debt limit talks in Washington, arranged to meet Saturday on the G-7 sidelines with leaders of the so-called Quad partnership, made up of Japan, Australia, India and the U.S.

As G7 attendees made their way to Hiroshima, Moscow unleashed yet another aerial attack on the Ukrainian capital. Loud explosions thundered through Kyiv during the early hours, marking the ninth time this month that Russian air raids have targeted the city after weeks of relative quiet.

G7 leaders and invited guests from several other counties on Saturday are also scheduled to discuss how to deal with China’s growing assertiveness and military buildup as concerns rise that it could try to seize Taiwan by force, sparking a wider conflict. China claims the self-governing island as its own, and its ships and warplanes regularly patrol near it.

In a bit of dueling diplomacy, Chinese President Xi Jinping is hosting the leaders of the Central Asian countries of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan for a two-day summit in the Chinese city of Xi’an.

The G7 leaders are to discuss 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.

A U.S. official said the leaders on Saturday would issue a joint communique highlighting a common approach toward dealing with China, as well as outlining new projects in the G7’s global infrastructure development initiative, which is meant to offer countries an alternative to China’s investment dollars.

The G7 includes Japan, the United States, the United Kingdom, France, Germany, Canada and Italy, as well as the European Union.

Associated Press writers Adam Schreck and Mari Yamaguchi in Hiroshima, Japan, Raf Casert in Brussels, Hanna Arhirova in Kyiv, Ukraine, and Fatima Hussein in Washington contributed to this report.