South Korea and the United States will conduct their annual military training this week but the drills will be smaller because of COVID-19, Seoul said Sunday.

The nine-day exercise that begins Monday is still likely to infuriate the North, which has long considered them rehearsals for invasion.

"The upcoming annual training is a computer-simulated command post exercise that is strictly defensive in nature," the Joint Chiefs of Staff said in a statement, adding they went ahead with plans after considering the pandemic.

The drills come in the early months of a new US administration under President Joe Biden, with nuclear talks between Pyongyang and Washington deadlocked.

The nuclear-armed North -- which attacked its neigbour in 1950 and triggered the Korean War -- has regularly been angered by military exercises between the US and the South.

The allies decided to conduct the combined exercise for "the maintenance of combat readiness posture and to support diplomatic efforts for denuclearisation and establishment of peace on the Korean peninsula," the statement said.

There are close to 30,000 US troops stationed in South Korea, and their annual drills with tens of thousands of South Korean soldiers have always angered the North -- with Pyongyang condemning the manoeuvres as offensive plans.

But following the first summit between the US and North Korea in Singapore in June 2018, then US president Donald Trump said Washington would suspend the "very provocative" joint military exercises with South Korea.

But a second meeting held in Hanoi in February 2019 broke up early with no progress towards Washington's goal of getting the isolated North to abandon its nuclear weapons programme.

Experts say North Korea may use the upcoming military drills to launch fresh provocations against Washington as it seeks to test the new Biden administration.