Setbacks have plagued negotiations on the North's nuclear activities
The US says there is "no decision" on removing North Korea from its terrorism blacklist - a factor in the deadlock over the North's nuclear disarmament.
The US reiterated that such a step could not be taken until a reliable verification process was established.
Earlier media reports quoting South Korean and US government sources said the two countries were close to a deal.
The disarmament process had seemed close to collapse after the latest row between Pyongyang and Washington.
North Korea began disabling its Yongbyon nuclear reactor in August, but lately it has made moves to reassemble the plant after a US refusal to remove it from the terror sponsors' list.
US Secretary of State Condoleezza Rice spoke to her partners in the North Korean nuclear talks on Thursday but no decision was made to strike Pyongyang from a US blacklist, officials said.
"No decision has been taken yet... We are where we were yesterday and the week before and the month before on that issue," said state department spokesman Sean McCormack.
The US nuclear negotiator Christopher Hill met North Korean officials for talks in Pyongyang last week - and it was there that a breakthrough was achieved, South Korea's Chosun Ilbo newspaper quoted a key government official in Seoul as saying.
The Washington Post quoted sources close to the Bush administration as saying the North could imminently be removed from the terror sponsors' list.
No named source has confirmed the imminent prospect of a deal.
Analysts say such a deal could halt the recent rapid downward spiral in bilateral relations.
In recent days, North Korea is reported to have fired two short-range missiles into the waters off the west coast of the Korean peninsula, and is suspected to be preparing a fresh launch.
It has also expelled UN inspectors from the Yongbyon plant.
North Korea badly wants to come off the US list of state sponsors of terrorism in order to access international aid and loans, and as a step towards its diplomatic rehabilitation.
Meanwhile, in Washington a deal would represent a big foreign policy victory for an administration in its final weeks - though the deal would be bitterly opposed by hawks.
This is just the latest phase of a long negotiation process that persists but is plagued by setbacks.
According to this particular deal, reached in six-party talks in February 2007, the North gains material and political concessions in exchange for nuclear disablement.
But the process is constantly prey to the tensions between North and South Korea - which remain technically still at war - and strains in the wider region.
In the latest spat, the North warned that "the situation in the waters off the frontal area on the west coast of Korea has become so tense that a naval clash may break out".
There is also speculation about the health of the North's leader, Kim Jong-il.
Friday was the anniversary of the founding of the Korean Workers' Party, but Mr Kim's presence was not mentioned in state news agency reports of the public celebrations.