North Korea carried out a “very important test," state media reported Sunday, at a satellite launching facility that the U.S. previously said North Korea had partially dismantled and agreed to close as part of denuclearization efforts.

Pyongyang didn't say what type of test was conducted, but North Korea's KCNA news agency said it took place at the Sohae Satellite Launching Ground, which experts believe the country has used to test rockets.

State media said the test will have “an important effect on changing the strategic position of (North Korea) once again in the near future.”

NORTH KOREA TO TRUMP: STOP CALLING KIM JONG UN ‘ROCKET MAN’, OR WE’LL CALL YOU A ‘DOTARD’

North Korea claims the satellite launches are part of a peaceful space program, but experts say they are likely disguised tests for ballistic missiles and rocket technology.

The new test comes amid a deadline set by Pyongyang, demanding the U.S. relieve sanctions and change its policy on North Korean denuclearization by the end of the year.

Denuclearization talks have stalled between the U.S. and North Korea since the Vietnam summit in February over how much sanctions relief Pyongyang would get for dismantling its main nuclear complex.

"We do not need to have lengthy talks with the US now, and denuclearisation is already gone out of the negotiating table," the North Korean envoy to the UN, Kim Song, told the BBC on Saturday.

In response to the remarks by North Korea, President Trump wrote on Twitter that he believes Kim Jong Un doesn't want to "void his special relationship with the President of the United States or interfere with the U.S. presidential election in November."

"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 wrote. "North Korea, under the leadership of Kim Jong Un, has tremendous economic potential, but it must denuclearize as promised. NATO, China, Russia, Japan, and the entire world is unified on this issue!"

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A statement released by North Korea’s United Nations ambassador said denuclearization is off the table and added that lengthy talks with the U.S. are unnecessary, claiming the Trump administration is pursuing a “hostile” policy against North Korea in an attempt to “stifle” it.

The Associated Press contributed to this report.