North Korea has warned the United States will pay a "due price" if it succeeds in pushing harsher sanctions through the UN.

The Security Council will this afternoon vote on a resolution put forward by the US following the secretive state's sixth nuclear test earlier this month.

In a statement on a possible ramping up of sanctions, North Korea's foreign ministry promised moves that would "cause the US the greatest pain and suffering it had ever gone through in its entire history."

The United States originally proposed the Security Council impose an oil embargo, halt textile exports and impose a travel and financial ban on leader Kim Jong Un.

It presented the proposals, which represented a departure from what had been military-focused rhetoric from Donald Trump, for a vote of the 15-member council.

But on Sunday night US officials appeared to tone down their demands, scrapping the asset freeze and softening restrictions on North Koreans working overseas.

Analysts suggest the changes are an attempt to encourage support for the measures from Russia and China, both of which maintain ties with North Korea.

Recent months have seen an alarming escalation in tensions between the isolated Korean state and the US, with Pyongyang launching increasingly ambitious missile tests and Mr Trump promising "fire and fury" in response.

On September 3rd Mr Kim provoked global outrage with a test of what North Korea claimed was a hydrogen bomb.

The latest Security Council vote is regarded as a test of the international community's resolve on the crisis - and private talks on its content have been ongoing between China and the US.