North Korea has issued a veiled threat to the US over its deadline for progress in nuclear talks, saying it is up to Washington to decide “what Christmas gift” it receives from Pyongyang at the end of the year.

Kim Jong-un’s administration has been trying to increase pressure on the US to offer meaningful relief from crippling economic sanctions, saying it will not proceed with its denuclearisation programme without it.

But US negotiators have dismissed North Korea’s promise to walk away from talks if concessions are not offered by the 31 December, calling it an artificial and arbitrary deadline.

In a statement on Tuesday attributed to Ri Thae Song, North Korea’s vice foreign minister for US affairs, Pyongyang accused the Trump administration of trying to buy time before the 2020 presidential election.

“The dialogue touted by the US is, in essence, nothing but a foolish trick hatched to keep the DPRK bound to dialogue,” Mr Ri said.

“What is left to be done now is the US option and it is entirely up to the US what Christmas gift it will select to get,” he added.

North Korea has previously referred to provocative military tests in such terms. After its first test of an intercontinental ballistic missile in July 2017, Mr Kim called the weapon a “package of gifts” to the Americans to mark the Fourth of July.

Since a rapprochement between Mr Kim and Donald Trump, North Korea has stuck to a self-imposed moratorium on nuclear and long-range missile tests, including the practice of firing projectiles directly over the Japanese mainland.

In recent months, however, North Korea has fired a series of short-range ballistic missiles using new multiple rocket launcher technology. While they pose no direct threat to the US, experts say the tests could enhance Pyongyang’s ability to strike Japan and its neighbour South Korea.

The last talks between the two sides were held in Sweden in October, but broke down after a single day over what the North Koreans described as the Americans' “old stance and attitude”.

Meanwhile, in the latest sign of the impact of International sanctions on North Korea, Pyongyang has announced the much-delayed completion of a new township in the mountains near Mount Paektu, described as the Kim dynasty’s ancestral homeland.

The town has been one of the government’s flagship infrastructure projects. Named Samjiyon, it includes housing for 4,000 families as well as public and industrial buildings spanning “hundreds of hectares”.

State media ran images of Mr Kim smiling as he cut the ribbon during an opening ceremony attended by thousands of people in the snow-covered town.