BEIJING (NYTIMES) - President Donald Trump's administration plunged the United States' Asian alliances into new confusion on Thursday (Aug 17) with conflicting signals over how to counter North Korea's nuclear threat, as the chief White House strategist said a military solution was impossible.

Three other leading officials of the administration - its top military general on a visit to China, and its defence secretary and secretary of state in Washington - effectively contradicted him, emphasising that Mr Trump was prepared to take military action if necessary.

The mixed messages about North Korea policy added to the sense of disarray coming from the White House, where Mr Trump appeared to have all but forgotten the crisis a week after he threatened an ad hoc "fire and fury" response to North Korean leader Kim Jong Un if he menaced the US.

Mr Stephen Bannon, the nationalist ideologue who is Mr Trump's chief strategist, said in an interview that there was "no military solution" in the Korean Peninsula, and that he might consider a deal in which US troops withdrew from South Korea in exchange for a verifiable freeze in the North's nuclear programme.

But General Joseph Dunford Jr, the chairman of the Joint Chiefs of Staff who was concluding a three-day visit to Beijing, dismissed the possibility of a US troop withdrawal. Speaking to reporters, he repeated the administration's earlier position that military action was not preferable but still possible.

General Dunford also said there were no plans to cancel US military exercises with South Korea scheduled to start on Monday - drills that North Korea could interpret as a new provocation.

Later in the day, after a meeting in Washington with Japan's defence and foreign ministers that was aimed partly at reassuring them, Defence Secretary James Mattis and Secretary of State Rex Tillerson expressed support for General Dunford's statements.

"Our approach has been endorsed by the President," Mr Tillerson told reporters.

He said the US and its allies would further intensify economic and diplomatic pressures on North Korea, and he praised China for its increased cooperation in those efforts.

President Moon Jae In of South Korea said on Thursday that Mr Trump had agreed to seek his consent before taking any military action against North Korea.