European Council President Charles Michel was cautious about a plan by Britain, the United States, Japan and Canada to ban imports of newly mined or refined Russian gold, Reuters reported.

"On gold, we are ready to go more into the details and to look if it's possible to target gold in a manner that would target the Russian economy and not in a manner that would target ourselves," Michel, who chairs EU summits, told a news conference as G7 leaders arrived.

The EU, which plans to ban imports of most Russian oil from the end of the year, also has reservations about U.S. attempts to impose a broad oil price cap or "price exception" to limit Moscow's energy revenues.

The price waiver could operate through a mechanism to limit or prohibit insurance or financing of Russian oil supplies above a certain amount. This could prevent side effects on low-income countries struggling with high food and energy prices.

Michel said G7 leaders would discuss a technical mechanism that would have the effect of limiting the price of oil through services related to oil insurance and exports.

"I'm careful and cautious, we are ready to go into the details. We are ready to take a decision together with our partners, but we want to make sure that what we decide will have a negative effect (on Russia) and not a negative effect for ourselves," Michel said.