Britain's Queen Elizabeth II has withdrawn all military ranks and royal patronage from her son Prince Andrew, who is being sued for abuse allegations in the United States.

Andrew will defend himself in the process as a private citizen, Buckingham Palace in London said on Thursday.

Earlier, more than 150 veterans signed an open letter calling on the Queen to strip her son of his titles.

Queen Elizabeth II's second son is accused of sexual abuse in connection with the affair surrounding convicted US sex offender Jeffrey Epstein.