US President Donald Trump has met Vietnam's president, Nguyen Phu Trong, in Hanoi, hours before Trump was due to meet North Korean leader Kim Jong-un for their second summit.
Trump and Trong, who is also general secretary of the ruling Communist Party, met at the grand, colonial-era presidential palace.
The two leaders are set to sign a commercial trade agreement on Wednesday before Trump lunches with Vietnam's prime minister, Nguyen Xuan Phuc.
On Wednesday evening, Trump is scheduled to meet Kim at the city's Metropole hotel, eight months after their first summit in Singapore, to discuss efforts to get North Korea to dismantle its nuclear weapons program.
Trump's courtesy call to the host nation's leadership is meant to provide Kim with a visualisation of a potential future should he give up his country's nuclear weapons in a deal with the US.
After a decade of bloody conflict that ended more than four decades ago, the US and Vietnam are now economic and strategic partners.
