The United States and South Korea have offered to keep their end of a defunct aid agreement with North Korea, provided Pyongyang takes "meaningful steps" to de-nuclearise.
In a joint statement released as US Secretary of State John Kerry wrapped up his first visit to Seoul, the two sides appeared to put the accent on diplomacy after weeks of threatening rhetoric from Pyongyang.
They say if North Korea makes the right choice they are prepared to implement the commitments under the 2005 Six-Party Joint Statement, referring to the aid-for-denuclearization agreement.
The United States and its allies believe the North violated the 2005 deal by conducting a nuclear test in 2006 and pursuing a uranium enrichment program that would give it a second path to a nuclear weapon in addition to its plutonium-based program.
Mr Kerry's visit coincided with preparations for Monday's anniversary of North Korean state founder Kim Il-Sung's birth, a possible pretext for a show of strength, with speculation focusing on a possible new missile test launch.
Missile launch "huge' mistake: Kerry
Mr Kerry, who will visit China and Japan next, says a missile launch now would be a huge mistake and a provocative act.
Recently, the North reportedly moved two Musudan ballistic missiles to its east coast - and South Korea is on alert. Estimates of the missiles' range vary, but some suggest they could travel 4,000 kilometres.
Speaking in the South Korean capital Seoul, Mr Kerry reconfirmed the United States' commitment to protecting itself and its allies, the BBC reports.
But he played down a US report that the North has a nuclear warhead, saying it was inaccurate to suggest North Korea has a working and tested device.
North Korea has increased its warlike rhetoric following fresh UN sanctions imposed after its third nuclear test in February and joint military manoeuvres by the US and South Korea, the BBC reports.
The North has said it will restart a mothballed nuclear reactor, has shut an emergency military hotline to the South and has urged countries to withdraw diplomatic staff, saying it cannot now guarantee their safety.
