Former New York City mayor Rudy Giuliani will receive a Presidential Medal of Freedom, the highest civilian honour, Donald Trump has announced on Truth Social.

Giuliani became known as America's Mayor after leading New York through 9/11. While he previously worked as Trump's personal lawyer, the pair have since parted ways.

The announcement comes two days after Giuliani sustained back injuries when a car he was a passenger in was struck from behind, police said.

Presidential Medals of Freedom are awarded to people who have made exceptionally meritorious contributions to the nation's prosperity, values, or security, world peace, or other significant public or private endeavours.

In the Truth Social post where Trump announced Giuliani's nomination, the president called him the greatest Mayor in the history of New York City, and an equally great American Patriot.

Past honourees include Muhammad Ali, Dr. Jane Goodall, Anna Wintour, and Michael J. Fox, among many others.

Giuliani has not yet publicly commented on the announcement, and it's unclear when he will formally receive the medal.

On Saturday evening, a car he was a passenger in was struck from behind in the US state of New Hampshire. All involved in the crash suffered non-life threatening injuries and were taken to the hospital, police said. His security guard reported that Giuliani suffered back injuries as well as lacerations and contusions. Reports suggest he has since left the hospital.

Giuliani's response to the September 11 terror attacks in New York drew widespread praise. Time magazine named him its Person of the Year for 2001, and Queen Elizabeth II presented him with an honorary knighthood.

In 2008, he made an unsuccessful run for US president and later became one of Trump's advisers during the latter's 2016 campaign.

While Giuliani had a historic rise to fame, in recent years he has faced personal and financial challenges. He joined Trump's legal team in 2018 and remained part of it through to the 2020 election, being involved in efforts to overturn Trump’s loss to President Joe Biden.

Giuliani was sued for defamation and ordered to pay two former Georgia election workers $148 million (£120 million). This court ruling also led to Giuliani filing for bankruptcy and losing his legal credentials.

In early 2021, Giuliani's legal work with Trump ended, although an adviser stated they remained allies and friends.