John Bolton, who served as Donald Trump's national security adviser before becoming a vocal critic of the president, has been criminally indicted on federal charges and is facing decades in prison.

The Department of Justice presented a case to a grand jury in Maryland on Thursday, and they agreed there was enough evidence to indict Bolton.

It comes after FBI agents searched Bolton's home and office in August as part of an investigation into the handling of classified information.

The indictment makes Bolton, 76, the third of the US president's political opponents to face charges in recent week, after former FBI Director James Comey and New York Attorney General Letitia James.

According to a 26-page indictment filed at a court in Greenbelt, Maryland, on Thursday, Bolton is charged with eight counts of transmission of national defence information (NDI) and 10 counts of unlawful retention of NDI.

Prosecutors accuse him of illegally transmitting top secret information about the US national defence using his personal email and other messaging apps.

"These documents revealed intelligence about future attacks, foreign adversaries, and foreign-policy relations," the document states.

It adds: "These documents included intelligence on an adversary's leaders as well as information revealing sources and collections used to obtain statements on a foreign adversary."

If found guilty, Bolton could face up to 10 years in prison for each charge.

"There is one tier of justice for all Americans," US Attorney General Pam Bondi said in a statement announcing the charges.

"Anyone who abuses a position of power and jeopardises our national security will be held accountable. No one is above the law."

Bolton has not yet commented, but he has denied any wrongdoing. His lawyer, Abbe Lowell, earlier said Bolton had handled records appropriately. He is expected to surrender to authorities on Friday.

According to CNN, Bolton is alleged to have shared the information with his wife and daughter. The indictment does not say who he is accused of providing the information to, describing them as "Individuals 1 and 2".

Both individuals are "related" to Bolton and have never held a US security clearance, prosecutors say.

The unauthorised information includes "diary-like entries from Bolton's time as the National Security Advisor" and were allegedly "printed and stored" at Bolton's home in Maryland.

Bolton was fired from Trump's first administration in 2019. His 2020 memoir, The Room Where It Happened, recounted his time working under Trump and portrayed him as a president who was ill-informed about geopolitics and whose decision-making was dominated by a desire to be re-elected.

The White House filed a lawsuit to block the book from being published, arguing it contained classified information and had not been properly vetted. A judge denied the request, and the book was released days later.

The US Department of Justice then opened an investigation into whether Bolton had mishandled classified information by disclosing certain information in the book.

Asked about the indictment on Thursday at the White House, Trump said he did not know about it, but added that Bolton was "a bad guy".

Trump has previously described Bolton as "grossly incompetent" and "a liar". He has also called for him to be prosecuted.

Asked in August about the investigation into Bolton, Trump said he did not "want to get involved" and had not directly ordered the searches of Bolton's home and office, but referred to Bolton as a "sleazebag".

Around the time the searches began, FBI Director Kash Patel posted on X: "NO ONE is above the law." The post did not name Bolton.

Bondi shared the post and added, "America's safety isn't negotiable. Justice will be pursued. Always."

Bolton, who served as George W Bush's UN ambassador, was among former officials critical of Trump who had their Secret Service protection stripped by the Trump administration in January.

He is the third Trump critic to be criminally charged since September.

New York City Attorney General Letitia James was criminally indicted on bank fraud charges in October.

Former FBI director James Comey was indicted in late September on charges of lying to Congress and obstructing a congressional proceeding.

The indictments followed a social media post from Trump, where he called on US Attorney General Pam Bondi, who leads the Justice Department, to prosecute his political opponents.

The post named Comey, James and Democratic Senator Adam Schiff, who oversaw Trump's first impeachment trial.

"We can't delay any longer, it's killing our reputation and credibility," he wrote.