The US has agreed to delay joint military exercises with South Korea until after the Winter Olympics, the Pentagon has said - just a day after Trump bragged about his 'nuclear button'.

Pentagon spokesman Colonel Rob Manning said President Donald Trump agreed to the delay in consultation with South Korean President Moon Jae-in.

Col Manning said in a brief written statement: 'The Department of Defense supports the president's decision and what is in the best interest of the ROK-US alliance.'

President Donald Trump agreed to the delay joint military exercises following a discussion with South Korean President Moon Jae-in (bottom right)

North Korean leader Kim Jong-Un (left) has repeatedly deplored the joint-military exercises, describing them as a provocation and a direct threat to Pyongyang. South Korean President Moon Jae-in, pictured right, talks with Trump on January 4

That was a reference to the US defense treaty with the Republic of Korea.

The decision was confirmed by a statement released by the Blue House, South Korea's presidential building, in Seoul, saying that Trump and Moon 'agreed not to host joint military drills during the period of Pyeongchang Olympics'.

Pentagon spokesman Colonel Rob Manning (pictured) said the Department of Defense supports the president's decision

North Korean leader Kim Jong-Un has repeatedly deplored the joint-military exercises, describing them as a provocation and a direct threat to Pyongyang, according to CNN.

The announcement comes on the heels of renewed communication between the North and South, with Kim ordering to revive a communication line that has laid dormant for nearly two years.

The hotline between Pyongyang and Seoul was utilized on Wednesday and Thursday, CNN reported.

The talks were sparked after Kim expressed hope that North Korea would be allowed to participate in the Winter Olympics during a New Year's Day address.

The decision pushes back a set of annual military exercises known as Foal Eagle, which normally are held between February and April.

Foal Eagle is a series of exercises designed to test the readiness of the two countries' militaries.

'America supports President Moon 100%,' Trump said to Moon following their 30-minute discussing on Thursday.

The decision to hold off on the military exercises is a significant difference between the President's approach earlier in the week, when Trump bragged in a tweet that his 'nuclear button' is 'much bigger and more powerful' than Kim's.

Despite the bellicose exchange, Trump sought to capitalize on the small but significant progress being cultivated on the Asian peninsula.

'With all of the failed "experts" weighing in, does anybody really believe that talks and dialogue would be going on between North and South Korea right now if I wasn't firm, strong and willing to commit our total "might" against the North,' Trump tweeted Thursday morning.

'Fools, but talks are a good thing!' he added.

The Winter Olympics begin on February 9 to 25 in Pyeongchang.