The G7 states continue to work on agreements on using Russia's frozen assets for Ukraine in accordance with international law, and it will happen "one day or another," U.S. Secretary of State Antony Blinken said.

"Progress on solutions also to use Russian sovereign assets for Ukraine was on the agenda… Being able to use these Russian sovereign assets to help rebuild Ukraine is critical, and it is also something that one way or another, one day or another is going to happen," Blinken said after a meeting between the foreign ministers of the G7 countries on Capri on Friday.

The G7 is "working on getting an agreement on that consistent with international law, consistent with different countries' laws," he said.

European Central Bank President Christine Lagarde earlier said at an event in Washington that the U.S. proposal to use Russia's frozen assets worth more than $260 billion for issuing bonds and for using the funds to help Ukraine posed legal risks.

"I have seen four different schemes or proposals to circumvent what many other jurists or lawyers - including in some administrations in this country - regard as a very serious legal obstacle that can be construed as a violation of the legal international order," Lagarde was quoted by The Financial Times.

The new information on plans for the Russian assets is expected to become available before the G7 summit, which will be held in Italy in June.

Bloomberg earlier reported, citing sources, that the United States had suggested creating a special mechanism for using bonds worth at least $50 billion, secured by profits from Russia's frozen sovereign assets, to its G7 partners. The discussion is at the initial stage, and some G7 members, including Germany and France, reacted to the idea with caution, a source told the agency.

UK Finance Minister Jeremy Hunt said on Wednesday that the U.S. plan is a very interesting idea and all proposals on the use of the frozen assets should be studied in an unbiased way, but in keeping with international legislation.