(Photo: Xinhua/ VNA)

In a tweet on Sunday, Mr. Trump said the Democrats’ decision to question his longtime fixer, lawyer Michael Cohen may have contributed to the failure of  negotiations as the questioning occurred simultaneously with the summit in Hanoi, Vietnam.

His national security adviser John Bolton, however, expressed a different view of the Hanoi meeting, calling it a success. Appearing in three television interviews on Sunday, Bolton said Trump  advanced US national security interests by rejecting a bad deal while working to convince Kim to agree to “the big deal that really could make a difference for North Korea.”

In another development, Australian Prime Minister Scott Morrison has praised  President Trump for trying to strike a deal with Chairman Kim to denuclearize the Korean peninsula. He said achieving denuclearization in North Korea was a difficult task, adding that President Trump had shown his resolute determination to promote negotiations and resolve the deadlock. Australian Foreign Minister Marise Payne said the two-day talks “continued a path in the right direction.” She said that denuclearization is a very complex matter that cannot be resolved overnight. She commended both leaders for their engagement and open exchange during the sessions.

The federal opposition was similarly upbeat about the Vietnam summit, with Labor senator Penny Wong saying “the only thing worse than no deal is a bad deal,” underscoring the benefit of a continuing dialogue between the two leaders.