The second summit of Democratic People's Republic of Korea top leader Kim Jong-un and United States President Donald Trump began on Wednesday in Hanoi, Vietnam, with both leaders expressing hope and confidence that this week's talks will be successful.

The two leaders greeted each other with warm smiles and shook hands for several seconds in front of the flags of their countries at the Sofitel Legend Metropole Hanoi hotel.

Trump said his previous talks with Kim in Singapore were a great success and the Hanoi meeting will "hopefully be equal or greater than the first". He added their personal relationship constituted the biggest progress and told Kim that the DPRK has tremendous economic potential.

Kim said he would do his best to produce a "great outcome" to be welcomed by all people.

The pair started a one-on-one meeting with their translators after the photo session. It was followed by a "social dinner" involving some of their top aides.