South Korea's Constitutional Court on Friday restored President Roh Moo Hyun to power, striking down an impeachment widely viewed as an attempt by opponents to halt his political agenda, which includes rapprochement with North Korea.

In a decision broadcast on national television, the court rejected impeachment charges of incompetence and mismanagement. The court president, Yun Young Chul, said a charge of illegal electioneering "was not serious or grave enough to justify the unseating of the president."

Roh's impeachment on March 12 -- the first ever of a South Korean president -- was marked by brawls in the National Assembly and candlelight vigils and rallies in support of Roh by student groups. Roh had been stripped of his constitutional powers pending the court's decision, leaving Prime Minister Goh Kun to serve as acting president.

"We accept the ruling of the Constitutional Court with a humble heart in front of the people and history," presidential spokesman Yoon Tae Young said.

The verdict, effective immediately, completes a reversal of fortune for Roh, whose impeachment actually rejuvenated his political standing through a massive public backlash against his ouster. Roh's return to power will leave the president and his allies in control of both the executive and legislative branches of South Korea's government. It marks the first time since the Korean War that political groups regarded as progressive -- favoring a focus on social programs, improved relations with North Korea and more independence from the United States -- have held such power.

With unprecedented authority to move forward with his agenda, Roh will immediately face a difficult balancing act: how to forge closer ties with North Korea, a policy supported by a majority of South Koreans, particularly the young, while trying not to alienate Seoul's main ally, the United States.

South Korea is pursuing broad dialogue with North Korea, including high-level military talks scheduled for May 26, even as international negotiations aimed at resolving the North Korean government's nuclear ambitions have bogged down. The stalemate is based, at least in part, on sharp disagreement between the Bush administration and the government of Kim Jong Il over how to dismantle the North Korean nuclear weapons program.

At the same time, the Uri Party, which supports Roh, advocates changes in the relationship with the United States. The party won control of the National Assembly in April 15 legislative elections, largely because of voter fury against the impeachment. Many party members are pressing for a review of South Korea's pledge last year to send 3,600 troops to Iraq, something the government has repeatedly delayed.

Top officials in Roh's government insist the president will remain firmly committed to the U.S. alliance.

Following his reinstatement, Roh "will emerge as a president with a much broader mandate, much stronger than any president in the past," said Ban Ki Moon, South Korea's foreign minister, in an interview last week. Ban conceded that Seoul faces the challenge of "how to manage South Korean-North Korean relations in a harmonious manner while addressing in a peaceful manner the nuclear issue," but added that the U.S.-South Korean alliance will "remain strong."

Roh's impeachment, a little more than a year into his five-year term, centered on a charge, described as "minor" by the National Election Commission, that he urged voters to support the Uri Party in legislative elections. Under election codes in South Korea, presidents are required to remain impartial during legislative elections.

But South Koreans -- in part because opposition parties were much more beleaguered by corruption scandals than the president -- largely saw the move against Roh as a political coup staged by his enemies. Public wrath centered on the Grand National Party, which was opposed to Roh's policy of rapprochement with North Korea as well as calls from within his administration for legislation to help the poor while increasing taxes on the rich.

It generated a sharp split in society. On one side were voters in their twenties and thirties, who represent almost half the electorate and largely supported Roh. On the other side were voters over 50, who still harbor memories of the Korean War and applauded his removal.

Relations with North Korea and the Bush administration are among Roh's many challenges. Analysts said he will need to focus on South Korea's nascent economic recovery and improving life for the poor.

"He's called himself an underdog and complained that he has been a half-president" because of the opposition's former control of the National Assembly, said Hahm Sung Deuk, professor of presidential studies at Seoul's Korea University. With the Uri Party now in the majority, however, "the people no longer will tolerate his statements that he is 'preparing for change,' or 'working on it.' He is a full president now, and he has to act like one."

Special correspondent Joohee Cho in Seoul contributed to this report.

Roh Moo Hyun returns to power after two months.