North Korean leader Kim Jong Un said Sunday Pyongyang was in the final stages of preparing to test an intercontinental ballistic missile (ICBM), South Korea’s Yonhap News reported.

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

The isolated country has been under United Nations sanctions since 2006 for its ballistic and nuclear missile tests. The country conducted its last test in Sept. 2016 after which the U.N. tightened restrictions against North Korea. The hermit nation had launched over 20 ballistic missiles in 2016 alone, including intermediate-range Musudan missiles.

However, experts said Pyongyang still has a long way to go before it tests a nuclear warhead capable of reaching the U.S.

Kim, in his Sunday speech, added that Pyongyang will ramp up preparations for potential nuclear strikes against South Korea and the U.S., if the two nations fail to abandon their joint military exercises. The North had repeatedly accused the joint exercises as rehearsals by Seoul and Washington to invade Pyongyang.

Kim, who President-elect Donald Trump called a “maniac,” did not mention the real estate mogul in his speech.

Meanwhile, a North Korean diplomat, who defected to South Korea in July, said Kim is likely to take advantage of the political situation in Washington and Seoul to complete its nuclear development by 2017.

“Due to domestic political procedures, North Korea calculates that South Korea and the U.S. will not be able to take physical or military actions to deter North Korea's nuclear development,” Thae Yong Ho told Yonhap News. “North Korea believes that relentless provocations must shift new [South Korean and U.S.] governments’ policy lines into more stability-focused ones.”

“As long as [Kim is in power] North Korea will never give up its nuclear weapons ... the North will not give them up even if the country is offered $1 trillion or $10 trillion in return. It’s not a matter of [economic] incentives,” he added.