The official KCNA news agency demanded on Monday that Washington sign a non-aggression pact with North Korea, establish diplomatic ties and make clear it would not hinder Pyongyang’s foreign trade.

"If the US does not express its will to make a switchover in its policy towards the DPRK, the DPRK will have no option but to declare that it cannot dismantle its nuclear deterrent force
at the talks," KCNA said.

DPRK are the initials for the Democratic People's Republic of Korea.

The talks between North Korea, the United States, China, Russia, Japan and South Korea are set to start on 27 August.

Last week, North Korea rejected ideas floated by the United States and others that fell short of a non-aggression pact, including written US pledges not to attack and talk of collective regional security guarantees for Pyongyang.

"The key to the solution of the nuclear issue on the Korean peninsula is for the US to make a fundamental switchover in its hostile policy towards the DPRK."

KCNA news agency

The KCNA statement also attacked US steps to put economic pressure on North Korea. These include building a coalition for curbing what Washington calls trade in counterfeit dollars and illegal drugs accounting for half of Pyongyang's annual hard currency income.

"The US continued pressure on the DPRK including economic blockade and military blackmail would only sour the atmosphere of the talks," KCNA said.

"The key to the solution of the nuclear issue on the Korean peninsula is for the US to make a fundamental switchover in its hostile policy towards the DPRK."

Analysts say that North Korea’s tough talk, albeit not new, is aimed at leveraging Pyongyang’s weak diplomatic hand and gain advance concessions. 

The Beijing talks will follow months of tension that began when Washington announced last October that Pyongyang was pursuing a covert nuclear weapons programme.

The crisis escalated early this year after North Korea expelled UN nuclear inspectors, pulled out of the nuclear Non-Proliferation Treaty and restarted an outdated reactor at Yongbyon, north of the capital, Pyongyang.