President George W Bush announced on Wednesday that the review of US policy towards North Korea had been completed and he had directed his national security team to hold "serious discussions" with Pyongyang.
South Korea urged the North to take a sincere approach to new talks, saying they were based on recent close co-operation between South Korea and the US.
Australia and Japan called the US move constructive.
The resumption of talks could clear the way for a new summit between the two Koreas.
The US initiative follows a review of relations with Pyongyang, focusing on its missile plans and the heavy North Korean troop build-up along the South Korean border.
President Bush has said the United States is willing to resume security talks with North Korea on its missile programme - hinting that sanctions could be relaxed if progress is made.
Strict verification
Earlier negotiations were broken off at the end of President Bill Clinton's administration, which came close to getting Pyongyang to limit its missile programme.
But President Bush has already said he does not trust the North's leader, Kim Jong-il, and that his aides will demand much stricter verification of any deal than the Clinton team would have required.
If talks do go ahead, they will cover what President Bush called a broad agenda - including the North's missile programme and massive deployment of troops near South Korea's border.
South Korea talks
The South Korean Government, which has embarked on a "sunshine policy" towards the North, hailed the move and urged Pyongyang to take a sincere attitude.
US Secretary of State Colin Powell is discussing the issue on Thursday with South Korea's Foreign Minister, Han Seung-soo.
North Korea is under US sanctions due to its designation as a state sponsor of international terrorism.
After the abrupt halt in negotiations with the US, which were intense during the last months of the Clinton administration, Pyongyang reacted angrily and cut off reconciliation talks with the South.
At issue is the North's long-range missile programme. US officials are concerned that Pyongyang's rockets could one day reach US territory.
North Korea's exports of missiles to Iran and other countries have also alarmed Washington. The North Korean leader said last month he intended to continue missile sales because his government needed the money.
Ship dispute
On Thursday, following another incursion, South Korea's Defence Minister Kim Dong-Shin threatened to use force against North Korean cargo ships if any ships came entered the country's waters again.