South Korea and the United States started their annual joint exercises on Sunday, after reducing the duration this year due to the current rapprochement with North Korea, the Defense Ministry announced here.
A combined field training of South Korean and USA troops got under way Sunday as scheduled, defense officials said amid a nascent peace mood on the divided peninsula.
The computer-simulated Key Resolve will be held for two weeks starting in mid-April.
Meanwhile, a total of nearly 300,000 South Korean servicemen and about 23,000 U.S. troops reportedly taking part in joint Foal Eagle maneuvers.
As many as 12,200 USA troops are expected to be mobilized in late April for further drills in South Korea.
A summit between Kim and U.S. President Donald Trump is anticipated by the end of May amid global diplomatic efforts to resolve the standoff over the North's nuclear program.
The exercises are usually held every year around March but they were postponed this year until after the Pyeongchang Winter Olympics.
Foal Eagle is due to last four weeks, half the duration of the drills previous year.
Tension on the flashpoint peninsula has shown signs of easing after the nuclear-armed North proposed summits with the South and their "imperialist enemy" the US.
In announcing the dates last month, Pentagon spokesman Marine Lt. Col. Christopher Logan insisted the exercises are "defense-oriented and there is no reason for North Korea to view them as a provocation".
The White House agreed, citing the need "to de-conflict the Olympics and our military exercises so that United States and Republic of Korea forces can focus on ensuring the security of the Games".
This year the exercises were pushed back and condensed because of the Olympics, which were held February 9-25 in Pyeongchang, South Korea.
Tension around Korean peninsula has reportedly shown signs of easing in recent weeks after North Korean leader Kim Jong Un has confirmed commitment to the inter-Korean talks and summits with U.S. and Japan. In a meeting last week with Chinese President Xi Jinping in Beijing, Kim expressed his willingness to discuss North Korea's potential de-nuclearization.
Pyongyang and Seoul are also scheduled on April 27 to hold a summit, their first in more than a decade.