By Caroline Gluck BBC correspondent in Seoul

The country is still trying to come to grips with one of its worst disasters - last week's underground train fires at the city of Daegu, in which more than 130 people died.

Mr Roh comes to power amid national mourning

It is also facing a deepening crisis over North Korea's nuclear ambitions, and a political scandal over revelations that hundreds of millions of dollars were secretly paid to the North just before a historic inter-Korean summit three years ago.

North Korea's alleged nuclear programme is likely to be the biggest test of Mr Roh's early days in office.

The crisis is already testing strained ties between Seoul and its close ally, Washington, over the best way to resolve the issue.

Mr Roh has said he does not agree with Washington's hardline policy of isolating the Communist state still further, and he has publicly opposed the use of force in resolving the stand-off.

Washington has said it favours a diplomatic resolution. But it has also stress that all other options, including economic and military measures, are still on the table.

Mr Roh - who has never visited the United States and once called for the withdrawal of US troops from South Korea, a view he now says was misguided - stood for office promising to work for a more balanced relationship between Seoul and Washington.

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

His win was helped, in part, by a wave of protests which many regarded as some of the largest shows of anti-American sentiment in recent years, following the acquittal of two American soldiers cleared of negligent homicide in the deaths of two South Korean teenagers.

But since his election victory, Mr Roh has been making clear he values the traditional alliance with the US.

He recently despatched envoys to Washington to try to repair damaged ties, and plans to travel to Washington soon for a meeting with President George W Bush.

Just hours after his inauguration, he will also hold talks in Seoul with visiting US Secretary of State, Colin Powell.

Mr Roh's team plays down talk of differences with the US.

"He's a rising star; and he's not very well known to the public," said lawmaker and friend, Chyung Dai-chul, who headed recent delegations to the US and Japan.

"Some areas have been misunderstood - including the perception among some that he supports anti-Americanism... that's not the case."

Mr Roh has said he supports the outgoing government's engagement policies with North Korea.

But following a political scandal after revelations that the government allowed secret, illegal payments to the North just before the historic inter-Korean summit, there are likely to be some adjustments to that policy.

Pointedly, he has said his administration will no longer follow the "sunshine policy" of outgoing President Kim Dae-jung, but instead, a "policy of peace and prosperity" in its dealings with the North.

Officials said the new administration wants to introduce more transparency in inter-Korean relations and hopes to achieve more widespread national consensus on future policy moves towards the North.

Fresh image

Mr Roh's election win was regarded by many as almost revolutionary.

In a country which reveres age and status, he is still relatively young, by South Korean political standards - just 56 years old - and never attended university.

Some areas have been misunderstood including the perception among some that he supports anti-Americanism - that's not the case Chyung Dai-chul, lawmaker

He has promised to usher in a new era in Korean politics, to tackle damaging regional divisions, end corruption, and reduce the gap between the rich and the poor.

He has vowed to continue with - and improve upon - the outgoing government's economic and financial reforms, including ensuring that the country's powerful conglomerates, or chaebol, conduct business more transparently.

The slogan for his new administration is "Participatory Government" - signalling his belief and hope that the Korean people will play more of an active role in shaping state affairs.

Mr Roh has pledged to listen to the people. As a first step, his transition team even invited the public to nominate on the internet who they thought should hold cabinet posts.

He is clearly taking office determined to push through broad reforms.

But he may be stymied in those efforts. While he has the mandate of the people, his party is in a parliamentary minority. And unless he can build political bridges, he may have to wait for more than a year, until the 2004 general election, in order to achieve what he has set out to do.