The U.S. Congressional Research Service has assessed that South Korea has emerged as the U.S.’s greatest ally in East Asia for the Obama administration.

The research service released a report Wednesday stating South Korea and the U.S. have maintained top-condition relations since 2008. It stated the two nations' ties have solidified with the recent passage of a bilateral free trade agreement in U.S. Congress and thanks to mutual assistance toward North Korea policies in the wake of the North’s sinking of the “Cheonan” naval ship and shelling of Yeonpyeong Island.

The report also noted that the recently-strengthened ties are greatly attributable to President Lee Myung-bak.

The research service forecast, however, that such close ties could face difficulties in the event South Korea sees a change in government during next year’s presidential election. It stated that if progressive forces win the presidential race, South Korea-U.S. relations would likely undergo a close evaluation.

The report added the main opposition Democratic Party and its supporters have been relatively more critical toward U.S. policies and have supported conciliatory policies for North Korea.