SEOUL, Aug. 21 (Xinhua) -- The combined forces of South Korea and the United States on Monday kicked off their joint annual war game that could raise the de-escalated tension on the Korean Peninsula.

The annually-held Ulchi Freedom Guardian (UFG) was scheduled to last through Aug. 31, according to local media reports citing South Korea's military authorities.

The computer-assisted simulation exercise would mobilize about 17,500 U.S. troops, including 3,000 reinforcements from outside South Korea. It was lower than last year's 25,000 U.S. soldiers.

Around 28,500 U.S. troops are stationed in South Korea as a legacy of the 1950-53 Korean War.

From the South Korean side, some 50,000 forces would join the military exercise. It was the same as last year's.

It was not known whether any U.S. strategic weapon, such as a nuclear-powered aircraft carrier and nuclear-capable bombers, would be mobilized.

The war game could re-escalate the eased tensions on the peninsula as the Democratic People's Republic of Korea (DPRK) has denounced it as a dress rehearsal for northward invasion.

Seoul and Washington claimed their joint war games, including the "Key Resolve" and "Foal Eagle" springtime joint military exercises, to be defensive in nature.

Tensions eased after U.S. President Donald Trump said last week that top DPRK leader Kim Jon Un made a "wise and well reasoned" decision not to fire missiles targeting the waters off the U.S. island of Guam.

According to the DPRK's official KCNA news agency, Kim had decided to delay the missile launch to wait and see what the U.S. would do next.

Before the suspended exchange of belligerent rhetoric, tensions mounted on the peninsula amid the war of words between Pyongyang and Washington.

Trump had warned the DPRK that the country would be met with "fire and fury" if it continues threat to Washington.

In response, the DPRK warned that it could fire four intermediate-range ballistic missiles towards the Pacific island of Guam, leading to Trump's warning that the U.S. military was "locked and loaded."

To mark 100 days in office, South Korean President Moon Jae-in told a nationally televised press conference Thursday that there would never be another war on the peninsula.

Moon pledged to prevent war from breaking out by all means, reiterating his earlier comments. He emphasized the need to resume dialogue with the DPRK for peace and the denuclearized peninsula.

Air Force Gen. Jeong Kyeong-doo, newly appointed chairman of South Korea's Joint Chief of Staff (JCS), said in the parliamentary confirmation hearing last week that it would be important to dissuade Pyongyang from its possession of nuclear weapons through dialogue and pressure.

Jeong said the eventual goal was the denuclearized peninsula, but he noted that the freezing of the DPRK's nuclear program would be necessary in the middle stage as the eventual goal would be hard to achieve at a time.