Trump: Hanoi will host second summit with North Korea's Kim

Trump made the announcement in a tweeted message on Friday, describing a meeting his representatives had in North Korea with their counterparts as “very productive.”

US special representative for North Korea Stephen Biegun had held three days of talks in Pyongyang to make preparations for the summit, according to the State Department.

In another tweet later, Trump said that North Korea “will become a different kind of Rocket - an Economic one!"

In their first summit last year, Trump and Kim reached a vague denuclearization agreement. The ensuing talks between the two sides have had little progress since then.

North Korea has complained that the US has done little to reciprocate for its actions so far to dismantle some weapons facilities and freeze its weapons testing.

Pyongyang has denounced what it called US "gangster-like behavior", saying Washington has betrayed the spirit of the June summit by making unilateral demands on the complete, verifiable and irreversible denuclearization, while keeping the sanctions in place.