U.S. President Donald Trump said on Sunday that North Korean leader Kim Jong Un risks losing “everything” if he resumes hostility and his country must denuclearize, after the North said it had carried out a “successful test of great significance,”.

Axar.az reports citing Reuters.

“Kim Jong Un is too smart and has far too much to lose, everything actually, if he acts in a hostile way. He signed a strong Denuclearization Agreement with me in Singapore,” Trump said on Twitter, referring to his first summit with Kim in Singapore in 2018.

“He does not want to void his special relationship with the President of the United States or interfere with the U.S. Presidential Election in November,” he said.

North Korea’s state media KCNA reported earlier on Sunday that it had carried out a “very important” test at its Sohae satellite launch site, a rocket-testing ground that U.S. officials once said North Korea had promised to close.

The reported test comes ahead of a year-end deadline North Korea has imposed for the United States to drop its insistence on unilateral denuclearization. Pyongyang has warned it could take a “new path” amid the stalled talks with the United States.

“North Korea, under the leadership of Kim Jong Un, has tremendous economic potential, but it must denuclearize as promised,” Trump said on Twitter.