North Korea's foreign minister has called U.S. Secretary of State Mike Pompeo’s words "alarming" as tensions over the North's nuclear programme have picked up again.

Ri Yong-ho’s comments came in the light of comments made by Mike Pompeo, who has urged other countries to keep up sanctions pressure on Pyongyang until it is seen taking action to stop its nuclear weapons programme.

At a regional forum in Singapore where Ri and Pompeo were both present, the U.S. Secretary of State said it was important to maintain "diplomatic and economic pressure" on North Korea to achieve "the final, fully verified denuclearisation".

Ri replied that North Korea "stands firm" in its commitment made at the June summit between US President Donald Trump and North Korean leader Kim Jong-un.

He added: "What is alarming, however, is the insistent moves manifested within the US to go back to the old, far from its leader's intention."

Ri and Pompeo only met face-to-face briefly, exchanging smiles, handshakes and a few brief words.

Also at Saturday's meeting, the U.S. delegation delivered a letter from U.S. President Donald Trump for Kim Jong-un. It is unclear what it contained.

Since the June 12 meeting between the U.S. President and North Korea’s leader, the two countries have vacillated between saying that North Korea is on the path to denuclearisation and that it needs to denuclearise completely before it gets sanctions relief.

Despite a warming of relations since June, which have resulted in North Korea dismantling part of a key rocket launch site in the north-west, and returning to the U.S. remains believed to be of 55 troops killed during the Korean War, the two sides continue to exchange strong words.

But reports last month based on U.S. intelligence leaks suggest Pyongyang is still upgrading its uranium enrichment sites.

(The above story first appeared on LatestLY on Aug 05, 2018 06:57 AM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).