Former White House National Security Adviser John Bolton says he is willing to testify at President Donald Trump’s impeachment trial in the Senate.
“I have concluded that, if the Senate issues a subpoena for my testimony, I am prepared to testify,” Mr Bolton said in a statement.
He has previously complied with the White House directive not to co-operate with the Democratic-led inquiry.
Mr Bolton would be the most senior former Trump adviser to testify.
Mr Trump, a Republican, was impeached by the Democratic-controlled House of Representatives last month. He was the third US president ever to incur such a congressional sanction.
Mr Bolton wrote on his website on Monday: “During the present impeachment controversy, I have tried to meet my obligations both as a citizen and as former National Security Adviser.
“Since my testimony is once again at issue, I have had to resolve the serious competing issues as best I could, based on careful consideration and study.”
The hawkish former national security adviser was fired by President Trump in September after 16 months on the job.
