Several South Korean civic groups called on the government Tuesday to terminate an agreement with the United States on sharing the cost of stationing American troops here.

The call came as the two allies began talks in Washington Tuesday on the renewal of the Special Measures Agreement (SMA) due to expire this year. Under the agreement, Seoul paid Washington 836 billion won (US$737.4 million) last year to support about 28,500 U.S. troops in South Korea.

The civic groups, including the Korea Confederation of Trade Unions and the Solidarity for Peace and Reunification of Korea (SPARK), held a mass rally in central Seoul demanding an end to the agreement.

"The SMA wrongly transfers costs incurred by the U.S. to South Korea," they said. "If an immediate withdrawal is impossible, South Korea should at least lower its contribution to a more reasonable level."

A recent report by the U.S. Congressional Research Service said Washington may call on Seoul to raise its share to at least 50 percent from the current 40-45 percent.

In June, the progressive SPARK argued that the U.S. had underestimated South Korea's contribution to the upkeep of U.S.

forces here, putting Seoul's share at 65.2 percent compared with the U.S. estimate of 42 percent.

The U.S. has maintained a military presence in South Korea since the 1950-53 Korean War, which ended in a cease-fire, leaving the two Koreas technically at war. (Yonhap News)