U.S. President Donald Trump urged North Korean leader Kim Jong-un on Sunday to "act quickly" and reach a deal with him to dismantle the North's nuclear weapons program.

Trump said on Twitter that he is the only one who can get Kim where he has to be. Trump added that Kim should "act quickly and get the deal done," and hinted at a possible third summit by ending the tweet "See you soon!"

Trump's tweet came about ten hours after the defense chiefs of South Korea and the U.S. announced a decision to postpone joint air exercises that were set for this month.

U.S. Defense Secretary Mark Esper called the decision an act of goodwill intended to promote diplomacy and urged Pyongyang to "return to the negotiating table without precondition or hesitation."

Esper and his South Korean counterpart Jeong Kyeong-doo announced the decision on Sunday after a meeting in Bangkok on the sidelines of the annual ASEAN Defense Ministers' Meeting-Plus.