North Korea has called US Republican presidential candidate Donald Trump's proposal to hold talks with the country's leader Kim Jong-un a nonsensical offer. A top Pyongyang diplomat said the offer was an attempt by the outspoken contender to use it for propaganda.

The North's response has come days after Trump had offered to directly speak to Kim over Pyongyang's contentious nuclear programme.

Speaking about Trump's willingness to talk to Kim, North Korea's ambassador to the UN, So Se Pyong, told Reuters: "It is up to the decision of my supreme leader whether he decides to meet or not, but I think his idea or talk is nonsense."

The envoy went on: "It's for utilisation of the presidential election, that's all. A kind of a propaganda or advertisement. This is useless, just a gesture for the presidential election."

Trump's remarks, if taken seriously, signalled a radical shift in the US's foreign policy towards the isolated nation, which has faced hard-hitting economic sanctions over the years. When questioned about Trump's policies on foreign affairs and how he would deal with the North if he is elected as the American president, he responded by saying: "I would speak to him [Kim Jong-un...I would have no problem speaking to him."

Latching on to Trump's comments, his opponent and Democrat presidential hopeful Hillary Clinton heaped scorn on him for openly offering to talk to Kim. Clinton's senior foreign policy advisor Jake Sullivan earlier said in a statement: "I suppose that makes sense for him [Trump], since he also praised Kim Jong-un for executing his uncle and seems to have a bizarre fascination with foreign strongmen like [Vladimir] Putin and Kim. His approach to foreign policy makes no sense for the rest of us."

The US does not have formal diplomatic relations with North Korea and Sweden acts as an intermediary between the two. The North largely views the US as a hostile power trying to declare war on the secretive nation.