PANAMA CITY (Reuters) - Panama has made progress stripping vessels from its registry that do not meet its flag's standards, the Central American nation's Maritime Authority said on Wednesday, responding to U.S. criticism that it allowed sanctioned countries to move ships with the Panamanian flag.

U.S. officials and congressmen have accused Panama of not taking action to help enforce sanctions on vessels and ship owners from countries including Russia, Iran and Venezuela. U.S. President Donald Trump has used these arguments to threaten the Panama Canal with a takeover.

Washington in recent years has requested that Panama, which gives its flag to 15% of the world's merchant fleet by tonnage, cancel the registration of dozens of ships targeted for transporting sanctioned commodities, including oil, or engaging in activities such as ship-to-ship transfers to disguise the countries or origin of cargoes.

Panama's Maritime Authority said the most recent evaluation of its registry by an independent fleet monitoring firm showed a 96.5% compliance with international safety and environmental standards.

"The Panama Maritime Authority ... has intensified its fleet purge efforts, removing from the registry those vessels that do not meet the required standards," it said in a release, adding that its registry was "not a haven for sanctions evasion."

"We have maintained a zero tolerance policy for any attempt to misuse the Panamanian registry," Ramon Franco, chief of Panama's merchant marine office, said in the release.

The authority did not disclose how many ships had been withdrawn from the registry.

In 2024, Panama's registry added a net 468 vessels for a total of 8,773 ships under its flag, according to data by S&P Global's consultancy IHS Markit, quoted by the Maritime Authority.