The ASEAN Regional Forum on Saturday will also involve South Korean Foreign Minister Kang Kyung-wha and North Korean Foreign Minister Ri Yong-ho.

Pompeo and Kang are likely to hold bilateral talks on the margins of the gathering. It remains uncertain whether Pompeo and Ri will meet, possibly in a trilateral setting with Kang.

If the three-way meeting is realized, there is speculation the top diplomats will discuss the issue of declaring a formal end to the 1950-53 Korean War, which ended in an armistice, not a peace treaty.

Pompeo is the US point man on negotiating the dismantlement of Pyongyang's nuclear weapons program in line with an agreement reached by US President Donald Trump and North Korean leader Kim Jong-un at their historic summit in Singapore last month.

North Korea is reportedly demanding a swift war-ending declaration to serve as a US security guarantee in exchange for its denuclearization.

In an interview with CNBC, Pompeo said the two sides have also talked about ways to develop the North's impoverished economy.

"We've told Chairman Kim, if we can denuclearize your country, there is a brighter future for the North Korean people," he said.

"We're convinced that he, too, shares that understanding that there has to be -- indeed he has directed -- better economic times for his own people."

Pompeo said Kim has expressed a desire for a market-based economy.

"We've spoken to him about the importance of allowing private dollars to come in," he added, "not just dollars from the United States, although I am confident there will be Americans who would want to invest in an open and rules-based North Korea, but Japanese, South Korean, Chinese too will all want to be part of the economic opportunity that there is in North Korea."

Pompeo will also travel to Malaysia and Indonesia before and after his visit to Singapore, according to Nauert. (Yonhap)