Ukraine has paused drone strikes on oil tankers using Russia’s Black Sea port of Novorossiysk ​after a request from US Vice President JD Vance, ‌the Financial Times said on Wednesday, citing Ukrainian officials.

The paper said last month’s request followed US alarm that Ukraine was destabilising oil markets and ​harming US firms by targeting tankers carrying crude piped from ​Kazakhstan to a Caspian Pipeline Consortium (CPC) terminal at the ⁠port.

Ukraine agreed not to target CPC infrastructure or non-Russian vessels ​as long as the latter were not under Ukrainian sanctions and ​were not carrying Russian oil or cargo, the newspaper added.

The White House, State Department and Vance’s office did not immediately respond to Reuters requests for ​comment outside business hours. Reuters could not immediately verify the ​report.

Ukrainian forces recently stepped up strikes on Russian energy infrastructure and other sites ‌in ⁠an effort Kyiv says aims at depriving Russia of resources to fund its military.

Black Sea drone attacks took out as much as a fifth of CPC oil loadings in July, four sources familiar with ​the data said, ​as the Russia-Ukraine ⁠war spilled over to hit sales by Kazakhstan and western oil majors.

Kazakhstan, which relies on the ​CPC route for crude exports, suffered a drop ​of 14% ⁠in oil production in July versus June, the sources said.

Chevron and Exxon Mobil are among the major Western oil companies operating there.

A ⁠US ​official confirmed to the paper that the ​administration had warned Ukraine to stop attacking non-Russian vessels in the Black Sea.