Updated

North Korea (search) has developed a long-range missile capable of targeting all of Japan and the U.S. territory of Guam, a South Korean newspaper reported Monday on the eve of the communist state's 55th anniversary celebrations.

South Korea's Defense Ministry, however, said it could not confirm the report in Chosun Ilbo, one of South Korea's leading newspapers.

The report comes amid speculation that North Korea could carry out a nuclear test on Tuesday, the anniversary of the formation of the Democratic People's Republic of Korea, as the country is known officially.

On Monday, South Korean Foreign Minister Yoon Young-kwan (search) warned that aggravating actions by North Korea would effect further talks on its suspected development of nuclear weapons.

Yoon, who met President Bush and Secretary of State Colin Powell last week, said Washington expressed concerns that North Korea might take threatening actions on Tuesday.

The "secretary of state believes that taking measures that worsen the situation are not only non-beneficial to North Korea, but also will not help to resolve the (nuclear) issue peacefully," Yoon told reporters. "I also hope that such an incident does not take place."

Chosun Ilbo quoted an unidentified government official as saying that the ballistic missile, with a range of 1,850 miles to 2,470 miles, was developed last year but has not yet been deployed.

The missile's range makes it more powerful than the 1,540-mile range Taepodong-1 missile (search), which can target all but the most far-flung of Japan's islands.

North Korea test-fired a Taepodong-1 missile in 1998 over Japan's main islands into the Pacific Ocean. The North also is believed to have an arsenal of up to 700 Rodong missiles that can hit targets as far as 800 miles away.

North Korea admitted running a secret nuclear weapons program last year, according to U.S. officials, who believe it may already possess one or two nuclear bombs and could produce more.

During last month's six-nation meeting in Beijing on the North's nuclear activities, North Korean delegate Kim Yong Il warned that his country could test a nuclear weapon and even prove that it had the means to deliver nuclear bombs.

North Korea has been demanding a nonaggression treaty from the United States before it dismantles its nuclear program. Washington has rejected the idea of a treaty, but Yoon said the Bush administration is "actively thinking" about addressing North Korea's security concerns.

"I believe they will take their proposals to the second round of six-nation talks," he said.

On Tuesday, some 20,000 troops, 150 tanks and other military vehicles are expected to be paraded through the reclusive nation's capital, Pyongyang. Some 50,000 participants including the country's leader Kim Jong Il will attend.

South Korea's JoongAng Ilbo, another leading newspaper, said the parade is likely to feature the Rodong missile.

This will be the first time in several years that the North will hold one of its military parades, which had been set aside because of the country's poor economy.