North Korean leader Kim Jong Un said on Sunday that his military was close to test-launching an intercontinental ballistic missile (ICBM).

North Korea tested ballistic missiles at an unprecedented rate during 2016, Although experts have said it is years away from developing an ICBM fitted with a nuclear warhead capable of reaching the United States the number of tests that North Korea attempted during 2016.

“Research and development of cutting edge arms equipment is actively progressing and ICBM rocket test launch preparation is in its last stage,” Kim said during a televised New Year’s Day speech.

ICBMs have a minimum range of about 5,500 km (3,418 miles). The intermediate-range Musudan missile that North Korea is also working on is designed to fly about 3,000 km (1,860 miles), posing a threat to South Korea and Japan, and possibly the U.S. territory of Guam.

The country has been under U.N. sanctions since 2006 over its nuclear and ballistic missile tests.

On Sunday U.S. State Department spokeswoman Anna Richey-Allen called on North Korea “to refrain from provocative actions and inflammatory rhetoric that threaten international peace and stability, and to make the strategic choice to fulfil its international obligations and commitments and return to serious talks.”

According to a senior U.S. intelligence official, President-elect Donald Trump’s first request for a special classified intelligence briefing was for one on North.

Kim also said that the North would continue to develop its nuclear capability if the United States and South Korea continue to conduct annual joint military exercises.

In February, North Korea launched a satellite into space. Many analysts saw this as a test of long-range ballistic missile technology.

North Korea appears able to mount a miniaturised nuclear warhead on a missile but it is still not able to develop the re-entry technology necessary for longer range strikes.