Roh Moo-hyun has become South Korea's 16th president

In what correspondents called a provocative move, the missile landed harmlessly in international waters east of South Korea, on the eve of President Roh Moo-hyun's swearing in.

Reports suggested the missile was a short range land-to-ship missile which fell 60 km (36 miles) from the Korean peninsula. North Korea has a self-imposed moratorium on long-range missile testing.

President Roh did not refer to the incident in his inauguration speech, but he did urge North Korea to renounce its nuclear ambitions.

US Secretary of State, Colin Powell, in Seoul for the ceremony, played down Monday's launch, stressing that it was an old type of missile and that US officials had heard such a launch was impending.

Later on Tuesday, North Korea complained that an American reconnaissance plane had intruded into its air space on Monday and on previous days.

HAVE YOUR SAY The uniting road ahead of the two Koreas is not an easy one R Josey, Canada/Korea Click here to read more of your comments

Pyongyang regularly makes such accusations, but this latest comes at a time of heightened tensions between North Korea and the US, at odds over the secretive state's nuclear programme.

Monday's missile launch will fan fears in Tokyo of a repeat of the incident in 1998 when North Korea fired a multi-stage rocket over Japan and into the Pacific Ocean, proving that all of its neighbour was in range of its missiles.

Japanese Foreign Minister Yoriko Kawaguchi called on North Korea for calm on Tuesday. "We will urge North Korea to take positive action for the sake of easing tensions and peace and stability," she said.

A Japanese defence agency source reportedly said two missiles were fired, at different times on Monday, but one of them failed. Japanese government officials said it was likely that North Korea would launch another missile on Wednesday.

China, North Korea's major ally, called for all parties to show restraint.

The missile launch is an immediate headache for Mr Roh, a former human rights lawyer who is a novice in global affairs.

"It is up to Pyongyang whether to go ahead and obtain nuclear weapons or to get guarantees for the security of its regime and international economic support," the leader said as he took office.

His inauguration ceremony outside the National Assembly was a low-key event, following last week's horrific fire on a subway in the South Korean city of Daegu, which killed at least 133 people.

Mr Powell described Monday's missile launch as "fairly innocuous" and "not surprising".

But he stressed that North Korea must give up its nuclear ambitions "once and for all", if its people were to have a better future.

President Roh, who wants to engage his country's northern neighbour in dialogue, has expressed concern at tough US rhetoric against Pyongyang.

Mr Powell said he had reassured Mr Roh on this issue, stressing that "the United States has no plans to invade North Korea. There are no armies on the march". But he said that he refused to rule out military force as an option.

North Korea wants direct talks with the US on the nuclear issue, but Mr Powell said Mr Roh understood Washington's view that it must be solved on a multilateral basis.

Roh Moo-hyun Former human rights lawyer Imprisoned for political activism At 56, considered young to be leader Click here for profile

Mr Powell also announced Washington's pledge of food aid for North Korea this year, although the promised amount - up to 100,000 tonnes - is less than the amount the US contributed last year.

He stressed that such aid was distinct from the political tensions between the two countries. North Korea has been embroiled in a tense stand-off with the US since American officials said last October that Pyongyang had admitted to a secret nuclear programme, a charge North Korea denied.

In recent months the US has voiced increasing frustration at what it sees as the unpredictable behaviour of the country and its ruler, Kim Jong-Il.

Roh hamstrung

In addition to continued engagement with North Korea, Mr Roh has pledged widespread economic and social reforms.

But his party does not have a parliamentary majority and he could find it hard to push through his reformist agenda.