Seoul, South Korea ? North Korea would respond to a pre-emptive U.S. military attack with an “annihilating strike and a nuclear war,” the state-run media said Monday, heightening anti-U.S. rhetoric amid close scrutiny of its missile program.

The Korean Central News Agency, citing an unidentified Rodong Sinmun newspaper “analyst,” accused the United States of increasing military pressure on the isolated communist state and basing new spy planes on the Korean Peninsula.

The North Korean threat of retaliation, which is often voiced by its state-controlled media, comes amid U.S. official reports that Pyongyang has shown signs of preparing for a test of a long-range missile. North Korea claims that it has the right to such a launch.

On Friday, Pyongyang accused the United States of driving the situation on the Korean Peninsula “to the brink of war,” and said it is fully prepared to counter any U.S. aggression.

Monday’s report accused Washington of escalating military pressure on the country with war exercises, a massive arms buildup and aerial espionage by basing new spy planes in South Korea.

South Korean passengers watch a television broadcasting undated image North Korea launch missiles at the Seoul Railway Station in Seoul, Wednesday, July 5, 2006. North Korea on Wednesday test-launched 10 short-, medium- and long-range missiles, Yonhap news agency reported, citing South Korean intelligence officials.

“This is a grave military provocation and blackmail to the DPRK, being an indication that the U.S. is rapidly pushing ahead in various fields with the extremely dangerous war moves,” the dispatch said.

“The army and people of the DPRK are now in full preparedness to answer a pre-emptive attack with a relentless annihilating strike and a nuclear war with a mighty nuclear deterrent,” the report said.

DPRK stands for the North’s official name, the Democratic People’s Republic of Korea.

North Korea routinely accuses the U.S. of aerial espionage, issuing a tally of such flights at the end of every month. The U.S. military doesn’t comment, although it acknowledges monitoring North Korean military activity.

Washington and Japan have said in recent weeks that spy satellite images show North Korea has taken steps to prepare a long-range Taepodong-2 missile for a test-launch.

Estimates for the range of the missile vary widely, but at least one U.S. study said it could be able to reach parts of the United States with a light payload.

Speculation that Pyongyang could fire the missile has waned in recent days since the country’s top ally and a major source of its energy supplies, China, reportedly urged North Korea not to go ahead with the test.