WASHINGTON (Yonhap News) -- A close partnership between the air forces of South Korea and the United States will continue regardless of which model Seoul picks for its next-generation fighter jets, a senior U.S. official said Friday.

"They are strong partners and allies and I think will remain so in any situation going forward," Secretary of the Air Force Michael Donley said in a Pentagon press briefing.

South Korea is in the process of selecting a contractor for the supply of 60 advanced jets to replace its aging fleet of F-4s and F-5s, a landmark acquisition program worth about 8.3 trillion won ($7.4 billion).

The three competitors for the contract are Lockheed Martin's F-35 stealth jet, Boeing's F-15 SE and the Eurofighter Tranche 3 from European Aerospace Defense and Space Co.

The winner will likely be announced as early as June.

Donley, the top civilian official in the Air Force, emphasized that the decision is entirely up to South Korea.

"These are individual national decisions, and we continue to support our South Korean allies in their selection process, providing the data that they need to make their decision," he said.

South Korea's defense procurement officials said they will carefully review the terms of the contracts offered by the three firms.

Critics say South Korea is excessively dependent on the U.S. for the purchase of fighter jets and other tactical equipment.

In 2002, South Korea chose Boeing for the supply of 40 F-15Ks.

Others, however, point out the importance of interoperability with existing military goods and systems. The U.S. is South Korea's main ally, deploying some 28,500 troops on the peninsula to help deter North Korea's aggression.

Earlier this week, the EADS, a European consortium, proproposed $2 billion in investment in South Korea's own fighter jet development project if it wins the upcoming deal.