Russia moved closer Sunday to defaulting on international debt payments for the first time in a century.
Interest payments totaling $100 million on two bonds were originally due May 27, but carried a 30-day grace period.
Russia has struggled to make such payments due to restrictions on its financial activities and sanctions imposed in response to its invasion of Ukraine that began in late February.
Russian forces launched new missile attacks Sunday on Ukraine's two biggest cities, the capital of Kyiv and Kharkiv.
Kyiv Mayor Vitali Klitschko said at least two apartment buildings in the city were hit, leaving at least one person dead, and four others injured.
Russia also ramped up its use of cruise missiles, striking targets across northwestern Ukraine. Air raid sirens blared in several cities.
"It's more of their barbarism," U.S. President Joe Biden said of the Russian strike on Kyiv as he appeared at a G-7 welcoming ceremony with Chancellor Olaf Scholz of Germany.
Russia's invasion of Ukraine is a key focus of the summit. Ukrainian President Volodymyr Zelenskyy is due to address the meeting Monday.
Biden said that the United States and the other G-7 economies will ban the import of Russian gold, the latest sanction imposed on Russia in response to its invasion of Ukraine, now in its fifth month.
The leaders of the G-7 nations - Canada, France, Germany, Italy, Japan, the United Kingdom and the United States - are trying to maintain unity against Russia, even with the war's growing toll on the global economy, including in the U.S., which is confronting a four-decade high surge in consumer prices.
The new attack on Kyiv came a day after the withdrawal of Ukrainian troops from the eastern city of Sievierodonetsk, a major victory for Russia after weeks of fierce fighting.
Russia now controls virtually all of the Luhansk province, part of the eastern Donbas region that Moscow is trying to take over, one of its major war aims.
Ukraine said Russian forces had fully occupied Lysychansk, a neighboring city of Sievierodonetsk, in the eastern Luhansk region. Moscow claimed it had encircled about 2,000 Ukrainian troops in the area.
Some information for this report came from The Associated Press and Reuters.