Christopher Wray, the head of the Federal Bureau of Investigations (FBI), says he will resign from his post before President-elect Donald Trump takes office next month.

Mr Wray announced his impending departure at an internal FBI meeting on Wednesday, according to the BBC’s US partner CBS News.

President-elect Donald Trump has publicly signalled his desire to replace Mr Wray with Kash Patel, a long-time loyalist who has called for “dramatically” limiting the FBI’s authority.

Mr Wray, who was nominated by Trump in 2017 to serve a 10-year term, has faced criticism during his tenure from Republicans due to the FBI’s investigations into Trump after he left office.

Speaking at the FBI meeting on Wednesday, Mr Wray said: “After weeks of careful thought, I’ve decided the right thing for the bureau is for me to serve until the end of the current Administration in January and then step down.”

“My goal is to keep the focus on our mission – the indispensable work you’re doing on behalf of the American people everyday,” he told his colleagues.

“In my view, this is the best way to avoid dragging the bureau deeper into the fray, while reinforcing the values and principles that are so important to how we do our work,” Mr Wray said.

He also addressed the FBI’s mission in his remarks, saying that the bureau’s goal to “keep Americans safe and uphold the constitution” will not change.

Trump appointed Mr Wray to lead the FBI after firing his predecessor James Comey following the FBI’s investigations into alleged contacts between the 2016 Trump campaign and Russia.

But in recent years, Mr Wray has fallen out of favour with the president-elect after the FBI assisted with a federal probe into Trump’s handling of classified documents, a case that has since been dropped.

Following his election to a second term, Trump said his pick for FBI director would be Patel – a former aide who has been a steadfast supporter of the incoming Republican president.