Vice President JD Vance has asked Ukraine to stop striking oil tankers using the Russian port of Novorossiysk, as the attacks affected Kazakh oil shipments and posed risks to American companies, according to Ukrainian officials cited by the Financial Times and reported by Reuters.

The request was made in July, the report said. Washington feared that Ukrainian attacks would destabilize the global oil market and harm US companies, as the strikes targeted vessels carrying oil from Kazakhstan via the Caspian Pipeline Consortium (CPC) system to a terminal near Novorossiysk.

Following the request, Ukraine agreed not to attack CPC infrastructure or vessels not linked to Russia, unless they are under Ukrainian sanctions or carrying Russian oil or other Russian cargo, the report noted.

In recent months, Ukraine has intensified strikes on Russian energy infrastructure. Kyiv says it aims to reduce Russia's resources for funding its military operations.

According to Reuters sources, drone attacks in the Black Sea in July reduced CPC oil loadings by about 20%. This affected Kazakh oil supplies and the operations of Western oil companies, including Chevron and ExxonMobil.

Kazakhstan, which exports most of its oil via the CPC system, cut production by 14% in July compared with June, sources told the agency.

Earlier, Kursiv reported that Kazakhstan may have lost $700 million in a month due to the attacks on CPC.