North Korea has issued a fresh warning of military action against a series of recent U.S. military asset deployments to South Korea.

In an editorial published Friday by Pyongyang's official Korean Central News Agency(KCNA), Kim Kwang-hak, a researcher at the North Korean Foreign Ministry’s Institute for American Studies, pointed to the U.S. B-1B bombers that flew over the Korean Peninsula on Tuesday in addition to the presence of an American nuclear-powered submarine and planned deployment of an aircraft carrier in waters off South Korea.

While rebuking U.S. President Donald Trump for waging reckless provocations toward the North, the researcher argued such actions give North Korea no other choice but to respond with its own military action.

He reiterated Pyongyang’s warning of “self-defense measures,” including enveloping the U.S. Pacific Island of Guam with its ballistic missiles.

The U.S. actions, he said, only strengthens the North’s resolve to fight back with “fire” and push it to pull what he described as a trigger on the strongest response.