The second summit between U.S. President Donald Trump and Democratic People's Republic of Korea (DPRK) leader Kim Jong Un will be held in the Vietnamese capital of Hanoi, Trump announced on his personal Twitter account. 

In his tweet, Trump said his representatives have just left the DPRK after "a very productive meeting," saying both sides agreed that the meeting will take place in Hanoi on February 27-28.

"I look forward to seeing Chairman Kim & advancing the cause of peace!" Trump said.

"North Korea (DPRK), under the leadership of Kim Jong Un, will become a great Economic Powerhouse," he added. "He may surprise some, but he won't surprise me, because I have gotten to know him and fully understand how capable he is. North Korea (DPRK) will become a different kind of rocket - an economic one!" 

Stephen Biegun, the U.S. special representative for the DPRK, held three days of talks in Pyongyang to prepare for the summit, the State Department said on Friday.

Read more: U.S., DPRK envoys plan more talks ahead of Trump-Kim summit

It said Biegun had agreed with his counterpart Kim Hyok Chol to meet again ahead of the summit.

In their talks in Pyongyang from Wednesday until Friday, Biegun and Kim Hyok Chol "discussed advancing President Trump and Chairman Kim's Singapore summit commitments of complete denuclearization, transforming U.S.-DPRK relations, and building a lasting peace on the Korean Peninsula," the State Department said.

Earlier this week, Trump announced the dates of his second summit with Kim and said it would be held in Vietnam in his State of the Union address, but didn't reveal the city.

Read more: Second Trump-Kim summit to be held in Vietnam February 27-28

The two leaders have a history in exchanging explosive words, with Trump calling Kim "little rocket man" and saying that "threats" from Pyongyang will be "met with fire and fury like the world has never seen." Meanwhile, Kim threatened to send missiles towards U.S. Guam, and called Trump a "mentally deranged U.S. dotard."

Read more: From taunts to talks: How Trump and Kim's relationship has evolved

But last year saw tensions easing on the Korean Peninsula as well as between Kim and Trump. The pair softened their rhetoric ahead of their Singapore summit on June 12, and from then on the two exchanged personal letters and Trump became effusive in praising Kim, calling him an "honorable leader" and saying they "fell in love."

Despite the sound momentum, it remains to be seen whether the second summit between Trump and Kim will lead to a detente in the DPRK nuclear talks, as little progress has been made since the first summit in Singapore and differences between the two sides remain over the scale of denuclearization, U.S. sanctions, and whether to issue a war-ending declaration.