Relations between the two sides remain tense over Pyongyang's nuclear and missile program and Seoul's joint military exercises with the United States. Trump then said America's military was "locked and loaded" if provoked.
North Korea's threats against Guam and its advancing missile capabilities, highlighted by a pair of intercontinental ballistic missile flight tests in July, have raised security jitters among many South Korean who worry that a fully functional ICBM in Pyongyang would force the United States to rethink whether to trade NY or Washington for Seoul in the event of a war on the peninsula. "I want all South Koreans to believe with confidence there will be no war", the president said.
But as State Department spokesperson Heather Nauert said on Tuesday, the USA has no plans of stepping them down.
The 10-day command post exercise known as Ulchi Freedom Guardian is to begin Monday and will involve tens of thousands of us and South Korean servicemembers.
"Also, even if the United States takes military action outside the peninsula, I am confident it will sufficiently consult with South Korea in advance if such action may increase tension between the South and the North", he said. The U.S. and other countries have accused North Korea of using export income to fund its banned weapons programs.
Pyongyang said Monday it had finalized a plan to fire four missiles less than 25 miles off Guam but state media said leader Kim Jong Un would wait to assess the US' next move before giving launch orders. When asked about potential unilateral U.S. action, he said, "that's purely speculative and a decision to do that would be by the president".
"The U.S. sought to put maximum pressure and sanctions through the latest U.N. Security Council resolution", the South Korean leader said.
Mr Trump's chief strategist Steve Bannon s aid in an interview with The American Prospect: "There's no military solution (to North Korea's nuclear threats), forget it".
Next week's start of annual U.S.
Moon Jae-in also declared, amid fears in South Korea that threats from President Donald Trump to unleash "fire and fury" on Pyongyang could lead to real fighting, that there would be no second war on the Korean Peninsula.
"If it is necessary, I will fly immediately to Washington and also visit Beijing and Tokyo", he said. "I do not necessarily believe that showed his determination to take military actions", he added. It also conducted two underground nuclear tests in 2016.
South Korean President Moon Jae-in has said US and South Korean policies are aligned on North Korea and promised there "will be no war on the Korean peninsula ever again".