Vice President JD Vance reportedly demanded Ukraine cease its attacks on oil tankers trafficking through Russian ports in the Black Sea, citing disruptions to the world energy markets.

The vice president spoke with Ukrainian President Volodymyr Zelensky on July 31, with a read-out from the Ukrainian side noting that the two “discussed the consequences of Russia’s war for global markets.” A report from the Financial Times, citing multiple Ukrainian officials, asserts that it was during this call that Kyiv was pressured to abandon attacks on non-Russian tankers carrying Kazakhstani crude oil to a Caspian Pipeline Consortium terminal at the Novorossiysk port.