North Korea has aggressively pushed back against the United State’s decision to re-list it as a state sponsor of terrorism, calling the move a “serious provocation,” a “violent infringement,” and “tantamount to another declaration of war.”

The tough talk is in response to President Donald Trump’s announcement on Monday that he’d return North Korea to a list of state sponsors of terrorism, a designation former President George W. Bush had lifted in 2008 in an effort to save a fragile nuclear deal with the rogue nation.

According to the Wall Street Journal, in a pair of statements published on Korean Central News Agency (KCNA) on Wednesday–one of which was attributed to North Korea’s Foreign Ministry–a defiant Pyongyang called the move a “serious provocation” and “violent infringement” on the country’s dignity. The remarks have raised concerns that North Korea could use the re-designation as justification for fresh missile or nuclear weapons tests.

In a separate statement, also released by KCNA late Wednesday, a spokesman for the Korea Asia-Pacific Peace Committee criticized the re-listing as “an extra-large provocation, tantamount to another declaration of war.”

In an interview with KCNA, a spokesman for the foreign ministry denied his government engaged in any terrorism, and said the designation only fueled the country’s commitment to retaining its nuclear arsenal.

“As long as the U.S. continues with its anti-DPRK hostile policy, our deterrence will be further strengthened,” he said, referring to North Korea by the initials of its official name, the Democratic People’s Republic of Korea, according to Reuters.

The remarks were the first from Pyongyang since Monday’s announcement from Trump about the re-designation of North Korea. The decision came a week after Trump’s 12-day, five-nation trip to Asia, during which he made clear he’d work to contain North Korea’s nuclear ambitions.