North Korea Friday repeated denials that it torpedoed a South Korean warship, saying Seoul's allegations brought the two nations close to war, amid international outrage at the attack.

It was Pyongyang's second denial in two days, after a South Korean-led investigation concluded Thursday that a North Korean submarine had torpedoed the corvette near the disputed border on March 26 with the loss of 46 lives.

South Korean President Lee Myung-Bak called an emergency meeting of his National Security Council Friday to discuss ways to punish the North.

Seoul's close ally the United States warned the North of consequences as Western nations and Japan condemned the attack.

But China, whose backing would be crucial in any attempt to impose new United Nations sanctions, has merely called for restraint by all parties.

The multinational investigation team said Thursday in a report it had overwhelming evidence that a North Korean torpedo split the Cheonan in two.

Members said torpedo sections salvaged from the seabed matched those used by the North, and displayed them at a nationally televised press conference.

In an unusually swift response, the North said Thursday the report was based on "sheer fabrication" and threatened "all-out war" in response to any attempt to punish it.

On Friday the communist state's official Committee for the Peaceful Reunification of Korea reiterated claims the South had fabricated the evidence.

"It just produced fragments and pieces of aluminium whose origin remains unknown as 'evidence', becoming the target of derision," a committee spokesman said in a statement on official media.

The Seoul government, the statement said, was seeking a boost in nationwide local elections on June 2, and looking for a pretext to go to war with the North "together with outside forces".

"The puppet group (Seoul government) has created such grave situation on the Korean peninsula that a war may break out right now," it said, using a warning it commonly delivers.

The North said it sees the current situation "as the phase of a war".

It threatened to respond to any retaliation with a "total freeze" of inter-Korean relations, abrogation of a non-aggression pact and a halt to cooperation between the two countries.

US lawmakers united behind Seoul after the publication of the investigation report, with some urging new sanctions on Pyongyang.

President Lee has promised "resolute countermeasures" but given no details.

His spokesman said the National Security Council, meeting for the first time in almost a year, would discuss the overall security situation and ways to respond to the torpedo attack.

"This was a serious provocation. There will definitely be consequences," US State Department spokesman Philip Crowley said Thursday without specifying countermeasures.

In a sign the United States was not expecting tensions abruptly to escalate, the head of the US military, Admiral Mike Mullen, said US troops had not been put on a state of alert.

The United States stations 28,500 troops in the South.

Secretary of State Hillary Clinton was en route to Japan, China and South Korea for talks on a previously scheduled visit. Defense Secretary Robert Gates said the Pentagon was also in "close consultation" with South Korea.

The United States has already hinted at one consequence -- no quick resumption of six-nation talks on North Korea's nuclear disarmament. Japan, one of the six-party members, made similar remarks.