This was reported by a Reuters source who gained access to correspondence between the countries.
These measures signal increased Western efforts to enforce the $60 price cap on Russian oil.
The introduced mechanism prohibits Western companies from providing transport, insurance and financial services to facilitate trade in Russian oil at prices above the limit.
Russia is increasingly using a ghost fleet of old tankers to transport its oil and circumvent restrictions. Panama, the Marshall Islands and Liberia have allowed some of these tankers to fly their flags, analysts said, reported Reuters.
This practice, known as “flag hopping,” allows some front companies created to trade Russian oil to use the flags of the three countries listed above and circumvent sanctions.
About 40 percent of the roughly 535 tankers in the dark fleet are owned by companies registered in the Marshall Islands, according to data analytics firm Lloyd’s List Intelligence.
A Reuters source claims that the letters in its possession contain warnings to Panama, the Marshall Islands and Liberia about increasing cases of circumvention of price restrictions on Russian oil established by the G7 countries, as well as about the risks associated with ships that do not have Western insurance.
The three countries themselves do not face sanctions. The three countries’ embassies in Washington did not respond to Reuters’ requests for comment.
The purpose of pressure from the United States and its allies is not to reduce the number of ships transporting Russian oil by water, but to tighten control over compliance with price ceilings and increase Russia’s costs when transporting oil.
Panama has generally responded to US requests to crack down on illegal activities, the Reuters source noted.
The US, EU and UK are asking Liberia and the Marshall Islands to raise awareness among traders that their flag should not be used on tankers carrying oil above the ceiling price.
The letters sent to the authorities of Panama, the Marshall Islands and Liberia were signed by the US Deputy Secretary of the Treasury Brian Nelson, who oversees the fight against terrorist financing and monitoring sanctions violations in the US government, the head of the international finance department of the British Treasury Lindsay White and the head of the financial services department of the European Commission John Berrigan.