WASHINGTON (REUTERS) - An American father and son accused of helping former Nissan Motor chairman Carlos Ghosn flee trial in Japan have asked US Secretary of State Antony Blinken to halt their impending extradition to the East Asian country.

On Saturday, the US Supreme Court denied an emergency request by lawyers for US Army Special Forces veteran Michael Taylor and his son, Peter Taylor, to pause a lower court order that cleared the way for them to be extradited.

A Feb 3 letter to Blinken seen by Reuters Wednesday from the Taylors' lawyers said "we do not believe there is any good reason to surrender these two American citizens."

The Justice Department declined to comment.

The State Department did not immediately respond to a request for comment.

The letter suggested the charges "are explained by the government of Japan's desire to save face, or at least to be perceived to be doing something to address their embarrassment."

The letter asked at a minimum that the extradition be delayed until the men received their second Covid-19 vaccine doses.

The Taylors' lawyers argue their clients could not be prosecuted in Japan for helping someone "bail jump" and that, if extradited, they faced the prospect of relentless interrogations and torture.

The Japanese embassy did not immediately reply for a request for comment.

A federal appeals court in Boston declined to prevent the Taylors' extradition while they appealed lower-court rulings.

The US State Department approved their extradition in October.

The Taylors were arrested in May at Japan's request after being charged with helping Ghosn flee trial in Japan. On Dec 29, 2019, the former executive escaped by hiding in a box and on a private jet before reaching his childhood home, Lebanon, which has no extradition treaty with Japan.

Ghosn was awaiting trial on charges that he had engaged in financial wrongdoing, including by understating his compensation in Nissan's financial statements. Ghosn denies wrongdoing.

Prosecutors said the elder Taylor, a 60-year-old private security specialist, and Peter Taylor, 27, received US$1.3 million (S$1.7 million) for their services.

The Taylors, who have been held without bail since their arrests, waged a monthslong campaign to press their case against extradition in the courts, media, State Department and White House with the aid of a collection of high-powered lawyers and lobbyists.