OHRID, Macedonia — Ukraine wants U.S. Navy warships, officials said Wednesday.

Russia’s Black Sea Fleet is based partly in ports on Ukraine’s Crimean peninsula — a source of tension between the two countries.

Ukraine’s interest in U.S. ships came up when Defense Secretary Robert Gates met with the Ukrainian Defense minister Wednesday at the annual South-Eastern Europe Defense Ministerial, Gates said.

"I explained that process to the minister including the need for Congressional approval," Gates told reporters. "I also advised that it would be some time before ships — U.S. ships of interest to Ukraine — would be available for transfer."

Gates also said both sides agreed to talk about the matter further at an upcoming meeting between U.S. and Ukrainian officials in December in San Diego.

Ukrainian Minister of Defense Yuriy Yekhanurov dismissed a reporter’s question on the subject.

"As usual, [the] press knows better what needs to be done in the military, so thank you very much for this advice," Yekhanurov said, speaking through a translator.

Gates did not specify what ships Ukraine wants, but a senior Defense official said they are Oliver Hazard Perry Class frigates.

First deployed in December 1977, Perry Class frigates’ armaments include torpedoes, a 76 mm gun and a Phalanx Close-In Weapons System, according to the Navy. Their missions include anti-submarine warfare and supporting amphibious expeditionary forces.

But Anne-Marie Slaughter, dean of the Woodrow Wilson School of Public and International Affairs at Princeton University, said the United States should proceed with caution.

"This is not a road we should be going down," Slaughter said in an e-mail to Stars and Stripes. "It’s a classic security dilemma, where one side (Ukraine) feels threatened and takes action that will be interpreted by the other side as aggressive, which in turn leads it to take action that will increase the perceived threat. The answer here is not arms, but creative and committed diplomacy by the U.S. And the EU together."

The U.S. Navy has transferred decommissioned frigates to Poland, Egypt, Bahrain and Turkey, which borders the Black Sea, along with both Ukraine and Russia.

Also Tuesday, Gates said he reaffirmed U.S. support for Ukraine joining NATO.

But recent political events in Ukraine have raised questions about whether Ukraine will become a member of the alliance. Last month, the ruling coalition collapsed, and the country’s new prime minister has indicated she favors stronger ties with Russia.

Gates said the U.S. government’s position toward Ukraine joining NATO remains unchanged in principle.

"Of course, we all have to deal with political realties," he added.