North Korea may be feeling the sanctions pinch, say analysts
North Korea has said it will not return to stalled international talks on its nuclear disarmament until sanctions against it are lifted.
North Korea's foreign ministry also repeated its call for a peace treaty to formally end the 1950-53 Korean War.
The US and South Korea have previously said the North must first show progress in ending its nuclear programme.
Sanctions against the North were tightened last year after nuclear and missile tests.
Pyongyang pulled out of six-nation talks on ending its nuclear programme last April following widespread condemnation of a long-range missile launch.
International pressure grew following a nuclear test in May - which drew UN sanctions and further missile tests.
If North Korea "goes out for the six-party talks, remaining subjected to the sanctions, such talks will not prove to be equal," the North's foreign ministry said in a statement published by the official Korean Central News Agency.
"The dignity of the DPRK [North Korea] will never allow this to happen."
The six-party talks group the two Koreas, plus the US, China, Japan and Russia.
Talks on a treaty to put a formal end to the Korean War would help build "confidence", the foreign ministry added.
The war ended in a ceasefire but not a peace treaty.
The six-party talks began in 2003, seeking to convince Pyongyang to give up its nuclear programme in return for aid and security guarantees.
North Korea is believed to have enough plutonium to build about six atomic weapons and has recently announced it is enriching uranium - a second route to building nuclear weapons.
Late last year, North Korea said it may be willing to return to the talks but has now set down conditions.
While discussions on the nuclear front have stalled, Seoul and Pyongyang have agreed to hold talks this week on developing the joint factory complex at Kaesong in the North.
More than 100 South Korean companies employ about 40,000 North Korean workers at the industrial zone.
The North also proposed last week to restart joint tourism projects and on Friday Pyongyang accepted an offer of food aid from Seoul.
Analysts say the North may be feeling the pinch from the new sanctions regime imposed last year.