The top US general restated Washington's "ironclad commitment" to the security of its close Asian ally, Japan, yesterday amid regional tensions over North Korea, telling his counterpart in Tokyo that "an attack on one is an attack on both of us".
Tillerson declined to comment on Bannon's statements but said pressure on North Korea was stronger than ever and included Pyongyang's ally, China.
South Korea has assured Thursday that there would be no war on the peninsula, referring to his de facto veto power on any possible us military action against North Korea.
The US and Japan have agreed to advance their multilateral security and defence cooperation with India, South Korea and Australia in view of North Korea's risky provocative behaviour, leaders of the countries have said.
However, White House chief strategist Steve Bannon said there was "no military solution" to North Korea's nuclear threats because of Pyongyang's massed artillery targeting the South Korean capital. "I think we have been quite clear as to what the policy and posture against North Korea is".
Japan's Kono said talks with Pyongyang would not be possible until it stopped its nuclear provocation.
U.S. President Donald Trump warned North Korea last week it would face "fire and fury" if it threatened the United States, prompting North Korea to say it was considering plans to fire missiles toward Guam.
"We are prepared, we are prepared militarily, we are prepared with our allies to respond, if that is necessary".
Bannon named the acting top US diplomat for East Asia, Susan Thornton, as one official he wanted out.
U.S. Defense Secretary James Mattis will meet his South Korean counterpart, Defense Minister Song Young-moo, later this month, the Pentagon said on Thursday after a phone call between the two officials on the eve of a U.S.
State Department officials, speaking on condition of anonymity because they weren't authorized to comment publicly, said Tillerson went out of his way to do so to demonstrate his confidence in Thornton, a career diplomat.
Japan, which hosts about 50,000 USA forces members, has sought support for global efforts to pressure North Korea.
But, he added, "what's unimaginable is allowing [Kim] to develop ballistic missiles with a nuclear warhead that can threaten the United States and continue to threaten the region".
The North's reaction to the "Ulchi Freedom Guardian" (UFG) joint military exercise that starts Monday will be key to determining what happens next.
Information for this article was contributed by Anne Gearan and Carol Morello of The Washington Post and by Matthew Pennington, Matthew Lee, Christopher Bodeen, Hyung-Jin Kim and Kim Tong-Hyung, Gillian Wong, Foster Klug, Robert Burns and Brian Skoloff of The Associated Press.