New measures announced by the leaders during the May 19-21 meetings will target sanctions evasion involving third countries, and seek to undermine Russia's future energy production and curb trade that supports Russia's military.

US officials also expect G7 members will agree to adjust their approach to sanctions so that, at least for certain categories of goods, all exports are automatically banned unless they are on a list of approved items.

While the allies have not agreed to apply the more-restrictive approach broadly, U.S. officials expect that in the most sensitive areas for Russia's military G7 members will adopt a presumption that exports are banned unless they are on a designated list.

Meanwhile, any change in language, including language specifying that certain trade is banned unless specifically exempted, by the G7 leaders may not necessarily lead to more bans immediately or indeed any change in Russia's posture.