A US conservative news website says Donald Trump is considering attending former Japanese Prime Minister Abe Shinzo's funeral.

Breitbart News asked the former US president in an exclusive interview if he would attend Abe's funeral.

It quotes Trump as responding that "We're going to see how it goes," adding, "we're talking to their family."

Trump is known to have had a close relationship with Abe, who was shot dead on Friday during a campaign speech.

Trump said in the interview that "every aspect of that man was just very special," and that "we had a special relationship."

He recalled that Abe was the first foreign leader to meet him in person after he won the US presidential election.

The Breitbart article says the two men shared dozens of phone calls, several visits to each other's countries and played golf several times together.