SEOUL (BLOOMBERG) - United States President Donald Trump and North Korean leader Kim Jong Un could meet in Vietnam's capital for their second summit on Pyongyang's nuclear ambitions, the South Korean newspaper Munhwa Ilbo said.

Denuclearisation talks have sputtered since Mr Trump and Mr Kim held an unprecedented meeting in Singapore in June last year, with Washington and Pyongyang each calling on the other to take action.

A second summit could address concerns to global security after Mr Kim piled pressure on Mr Trump by threatening in his annual New Year's address to take a "new path", if the US didn't relax economic sanctions.

US officials have met their North Korean counterparts in Hanoi for discussions to adjust scheduling for the talks, the newspaper said, citing high-level diplomatic sources in Seoul and Washington it did not identify. Government officials have not commented on the report.

Such a summit would be certain to grab global attention and help boost the profile of the host nation. But it also presents enormous security challenges for Mr Trump, the leader of the world's biggest economy, and Mr Kim, head of arguably one of the world's most paranoid states.

Vietnam is a long-standing ally of Pyongyang that has good relations with Washington. Speculation about the country's prospects as a summit site grew following North Korean Foreign Minister Ri Yong Ho's visit there from Nov 29 to Dec 2.

The South Korean newspaper JoongAng Ilbo previously reported that Mr Mark Lambert, a senior US State Department official handling North Korea issues, visited Vietnam in December. It was unclear whether he was in Vietnam at the same time as North Korea's foreign minister.

Hanoi - about a four-hour direct flight from Pyongyang and in airspace over countries friendly to North Korea - boasts several top-class hotels.

Vietnam's ruling Communist Party also has the security apparatus to squelch protests and keep curious onlookers far away from Mr Trump and Mr Kim.

Mr Trump has previously said he plans to hold a second meeting with Mr Kim as early as this month, although a date and location have not yet been announced.

Other places floated as hosts include Singapore, Mongolia and Switzerland.