China's ambassador in Port Vila says Vanuatu's Prime Minister Serge Vohor threatened him on the steps of parliament.
Bao Shusheng says the incident occurred when he went to see Mr Vohor to complain that the flag of Taiwan was still flying in Port Vila.
Mr Shusheng understood the flag was to have been taken down following a ruling by the council of ministers.
However Mr Vohor, who has been pursuing diplomatic links with Taipei despite his council's commitment to the One China policy, ordered the Taiwan flag to be raised again.
Mr Shusheng says he went to talk with the Prime Minister as he was leaving parliament, when Mr Vohor waved his fist in his face and then shoved the envoy's shoulder before promptly departing in his car.
"This is my understanding - he was threatening me. Otherwise why should he stretch his fist in my face? He didn't say any word about it. I could not understand. I think it's an insult."
Bao Shusheng says does not intend to make a formal complaint about the incident