President Donald Trump said on Thursday that he suffered a "terrible ordeal" during his impeachment.

In his first public comments since being acquitted by the Senate of abuse of office, he said he had been "put through a terrible ordeal by some very dishonest and corrupt people".

"They have done everything possible to destroy us and by so doing very badly hurt our nation," he said at a televised prayer breakfast with a Who's Who of Washington power brokers.

Speaking in an unusually raspy voice, Trump noted that he would be giving a statement at the White House later. He said he would discuss his determination that what happened during his impeachment cannot be allowed to "go on".