Police held two men for questioning in Hanoi, where US and North Korean leaders are meeting next week.
Impersonators of North Korean leader Kim Jong-un and US President Donald Trump have been questioned by police in Vietnam.
Kim impersonator Howard X and Trump lookalike Russell White were reprimanded after staging a “meeting” in Hanoi.
The pair have been released but told news agency AFP they were threatened with deportation.
It comes a week before a scheduled US-North Korea summit in the capital.
“They basically said stop doing the impersonation or we will kick you out of the country,” Howard X – a Hong Kong resident – told AFP.
He and Mr White took part in a faux summit in the capital, telling reporters they intended to scale down North Korea’s nuclear ambitions.