South Korea and the United States wrapped up their joint military exercise Thursday, a day earlier than scheduled, officials here said, spawning speculation that the move might be intended to help soothe North Korea.

The allies' Combined Forces Command in Seoul announced that it successfully completed its annual computer-assisted simulation drill, named Ulchi Freedom Guardian.

"This year's Ulchi Freedom Guardian exercise further strengthened our combined defense and enhanced the readiness of the Republic of Korea and the United States Combined Forces and the United Nations sending states," Gen. Curtis M. Scaparrotti, chief of the CFC, said in a press release. The U.S. general also leads the 28,500 American troops stationed on the peninsula.

The training, he added, was based on "realistic scenarios" and ensured the allies are fully prepared to defend South Korea in case of an emergency situation.

South Korea and the U.S. began UFG on Aug. 18, snubbing Pyongyang's fierce protest laden with war threats.

"We finished the UFG exercise today as evaluation showed its goal has been achieved," a CFC official said on condition of anonymity. "You can say that it came to an end a day ahead of schedule."

Some observers said the decision may be part of efforts to keep military tensions from soaring and to reach out to the North.

Although the North did not carry out its threat of a "pre-emptive attack," it continued to condemn the regular defense drill, shunning any formal dialogue with the South.

Just before the opening of UFG, Seoul proposed high-level talks with Pyongyang. The communist nation has kept mum on the offer.

The South also hopes for another event to get families separated mostly by the 1950-53 Korean War temporarily reunited.

The two sides also have yet to resolve some sensitive issues, including who will pay for the cost of the North Korean delegation to the forthcoming Incheon Asian Games.

More than 30,000 U.S. soldiers and 50,000 Korean troops took part in this year's UFG.

Ten other nations -- Australia, Britain, Canada, Columbia, Denmark, France, Italy, the Netherlands, New Zealand and Norway -- participated in it as well. All of them sent troops to the 1950-53 Korean War to help the South defend itself against the invading North.

The war ended in a truce, not a formal peace treaty, leaving the peninsula technically in a state of war.

The United Nations Command is still in operation to oversee the implementation of the 1953 Armistice Agreement.

A group of Swiss and Swedish soldiers belonging to the Neutral Nations Supervisory Commission monitored the exercise to ensure that it was in compliance with the Armistice Agreement, the CFC said.

UFG and other joint defense drills by South Korea and the U.S.

are carried out in the spirit of their Mutual Defense Treaty signed in 1953 and in accordance with the armistice, it added.

Those exercises highlight the longstanding military partnership between Seoul and Washington and contribute to ensuring stability and security on the peninsula, said CFC. (Yonhap)