Tillerson said the campaign differs from previous USA approaches to North Korea because of its "level of global unity", the "level of cooperation from China and others" and the "intensity" of the campaign.
"In close collaboration with our allies, there are strong military consequences if DPRK initiates hostilities", Defense Secretary Jim Mattis said, using the initials of the Democratic People's Republic of Korea.
"Together, we will deter and, if necessary, defeat any threat".
Japan has said it will introduce a new land-based defensive missile system and develop a "space unit" to protect its satellites against the renewed threat from North Korea.
Defence Secretary Mattis said that the U.S. would take immediate specific actions in the event of a missile launch towards USA or its allies.
"In light of this serious situation we face", the secretary said, "we are accelerating implementation of the 2015 guidelines for the U.S. -Japan defense cooperation and continue to realign U.S. forces in Japan and Guam".
The diplomatic option got an endorsement from an unlikely source Thursday, in an interview White House chief strategist Steve Bannon gave to the journal American Prospect.
The US general is on the last stop of an Asia tour that took him to China and South Korea and has been dominated by talk of the North Korean threat.
The term is sometimes used interchangeably with "pre-emptive" action, although the latter refers more often to forestalling an attack.
"Never has there been a time that calls for a more united and concerted response by the U.S. and Japan", he said. But he dismissed claims that any talks between Pyongyang, the USA and its allies could take place before the North agrees to abandon its nuclear ambitions.
"And I think that is the message that the president has wanted to send to the leadership of North Korea, and it was really in response to this ever-escalating levels of threat and rhetoric that were coming from the regime in Pyongyang", he added.
Beijing has banned most imports from North Korea to comply with United Nations sanctions.
On North Korea, with regards to its denuclearization, we agreed we would ramp up effective pressure.
The Chairman of the US Joint Chiefs of Staff Joseph Dunford said that the military alliance between his country and Japan was rock solid and reaffirmed the US' commitment towards the defence of its allies. The Japanese-administered Senkaku Islands are also claimed by China and Taiwan.
"If the US fleets come to this region, with further threats, and both sides have no space to retreat, then it would eventually turn into a regional conflict", said the 18-year-old.
Tillerson said the United States will continue to work diplomatically for negotiations that end with North Korea giving up its nuclear weapons.