North Korea on Sunday rejected fresh talks over its nuclear programme, dismissing overtures from the US and South Korea and calling instead for a peace treaty with its neighbour.
US President Barack Obama and his South Korean counterpart Park Geun-Hye on Friday said they were ready to engage with Pyongyang if the country agreed to give up its nuclear weapons.
But the North's foreign ministry said any negotiations on its nuclear programme were off the table until a truce signed at the end of the Korean conflict in 1953 is replaced by a full peace treaty.
"No issue in which the countries concerned including the US are interested can be settled unless a peace treaty is concluded before anything else," it said in a statement released on state media.
"If the US insists on its hostile policy, it will only see the DPRK's limitless bolstering of nuclear deterrence and the growth of its revolutionary armed forces," it added, using another name for North Korea.
North and South Korea remain technically at war under a truce signed to end the 1950-53 Korean War, and the two came to the brink of armed conflict this summer until a deal was sealed in August.
Tensions are still running high, however, and Pyongyang has threatened to conduct a fourth nuclear test as part of a weapons and missile program that it has pursued despite international sanctions.
The secretive country has long claimed it has technology capable of launching nuclear bombs at distant enemies, but experts question if it has acquired the sophisticated expertise needed to produce such weapons.
In a huge military parade this month the North displayed what it claimed were long-range ballistic missiles loaded with miniaturised nuclear warheads, though analysts said they could be mere mock-ups.
Speaking after his meeting with Park in Washington, Obama said if the North is willing to curb its nuclear programme, "I think it's fair to say we will be right there at the table".
But the North's foreign ministry said the only way to stop the "escalating tension" along the Korean peninsula from turning into "all-out-war" was with a full treaty "to put a definite end to the evil cycle of escalating confrontation and tension."