MANILA - Asean remains committed to de-escalating tensions in the Korean peninsula, said Asean secretary-general Le Luong Minh on Friday (April 28).

The top bureaucrat of the 10-nation grouping also confirmed in an interview that he has received a letter from North Korea on the crisis in the Korean peninsula, and has informed Asean members of the letter's contents.

The letter was sent to Mr Minh by North Korean Foreign Minister Ri Yong Ho, amid rising tension between Pyongyang and Washington as the United States steps up pressure on the isolated nation.

US officials said on Thursday that the US will tighten economic sanctions against North Korea to stop the regime's nuclear and ballistic missile programme.

Speaking to The Straits Times and Lianhe Zaobao ahead of a meeting of Asean leaders in the Philippine capital on Saturday, Mr Minh said that Asean has consistently called for de-escalation of tension and denuclearisation in the peninsula.

He also said the regional grouping will continue to be guided by these principles in dealing with the issue, adding that it will express its position consistently at the Asean Regional Forum (ARF), where North Korea is a participant.

The ARF will hold its meetings in August this year.

On the letter he received, Mr Minh said it contained North Korea's position about the ongoing crisis in the Korean peninsula.

Tensions in the Korean peninsula have escalated after North Korea carried out missile tests earlier this month and also threatened to launch a nuclear strike on Australia.

In the letter dated March 23 appealing for the support of Asean countries, Mr Ri had described the situation on the Korean peninsula as grave and criticised joint military exercises between the US and South Korea.

Mr Minh said in the interview on Friday: "I did receive a letter from the Foreign Minister of the Democratic People's Republic of Korea informing us of their position, what is happening in relation to the Korean peninsula."

"They asked me to share what was mentioned in the letter to my Asean colleagues, and I did (so)," he added.

Asean foreign ministers, who are meeting in Manila on Friday, have also expressed concern about the situation in the Korean peninsula, and are expected to discuss the issue further.

The issue is also likely to be on the agenda when Asean leaders meet on Saturday in Manila.

The leaders will also take stock of the grouping's progress in regional integration, its external relations, and exchange views on various regional and international issues - including freeing up trade across the region amid rising protectionist sentiment globally.