John Bolton, Donald Trump's former national security adviser, has pleaded not guilty to charges of mishandling classified information. The 18 charges stem from allegations he shared or retained sensitive materials, including some characterized as top secret. Bolton entered the plea after surrendering to authorities at a federal court hearing on Friday.

Bolton served during Trump's first administration but parted with the White House contentiously, becoming one of the president's most vocal public critics. The indictment makes Bolton, 76, the third of Trump's political opponents to face charges in recent weeks. He has insisted on defending what he calls his 'lawful conduct'.

Upon his arrival at the courthouse in Greenbelt, Maryland, Bolton was dressed in a dark suit and maroon tie, opting not to address reporters. He audibly declared, 'Not guilty, your honor,' before being released on his own recognizance, with a hearing scheduled for November 21.

Prosecutors accuse Bolton of using personal messaging apps and email to illegally transmit sensitive information that allegedly revealed intelligence about future attacks and foreign adversaries. Bolton maintains that his actions were lawful.

In a statement, he condemned the charges as part of a pattern of targeting by the Justice Department against those who Trump deems enemies. His attorney, Abbe Lowell, emphasized that Bolton's diary-like entries and communications were unclassified and previously known to the FBI.

The charges follow ongoing scrutiny of Bolton's handling of classified information. A prior investigation into Bolton, stemming from his book about his time in the Trump administration, did not lead to charges, though his actions were described by a judge as jeopardizing national security.

Amidst a landscape of legal challenges, Bolton's indictment follows recent criminal charges brought against other opponents of Trump, continuing the narrative of a politically charged legal environment.