Rex Tillerson
Rex TillersonReuters

U.S. Secretary of State Rex Tillerson on Thursday hinted that Washington would take a tougher strategy to confront North Korea's nuclear threat, but also stressed Pyongyang had no need to fear the United States.

North Korea, which is under UN sanctions, has repeatedly fired ballistic missiles and carried out nuclear tests in defiance of those sanctions.

Earlier this week, Pyongyang threatened to launch a series of "merciless" attacks on the U.S. if a U.S. Navy carrier violates its “sovereignty and dignity”. The threats came as the USS Carl Vinson was sailing towards South Korea in order to take part in joint drills between the two countries.

Tillerson, who spoke Thursday in Japan at the start of a three-country Asia tour, offered no details about what would comprise the "different approach" to North Korea the U.S. will pursue.

Speaking alongside Japanese Foreign Minister Fumio Kishida and quoted by The Associated Press, Tillerson did however, demand once again that North Korea "abandon its nuclear and ballistic missile programs and refrain from any further provocation."

He said his visit to Asia was designed to "exchange views on a new approach," echoing the comments of others in Washington, who have said Donald Trump wants to examine all options -- including military ones -- for halting the North's weapons programs.

At the same time, Tillerson stressed, "North Korea and its people need not fear the United States or their neighbors in the region who seek only to live in peace with North Korea."

State Department spokesman Mark Toner would not specify on Thursday what elements the new U.S. approach would entail, but added Tillerson had sought to emphasize that the U.S. prefers a peaceful solution and that the U.S. was taking issue with North Korea's government, not its people.

The U.S. Ambassador to the UN, Nikki Haley, said recently the United States is reevaluating its approach to North Korea and would consider “every option that's on the table.”

"We're not ruling anything out," she stressed.