By Philip Pullella

VATICAN CITY (Reuters) -Pope Francis has dismissed Bishop Joseph E. Strickland of Tyler, Texas, one of his fiercest critics among U.S. Roman Catholic conservatives, a Vatican statement said on Saturday.

It is very rare for a bishop to be relieved of his duties outright. Usually bishops in trouble with the Vatican are asked to resign before submitting a resignation, which the pope accepts.

Popes make such moves, considered drastic, when a bishop refuses a request to resign. Strickland is 65, 10 years shy of the usual retirement age for bishops. Strickland had said earlier this year that he would refuse to resign if asked.

Strickland, a prolific user of social media who was named to the diocese by the late Pope Benedict in 2012, tweeted earlier this year that he rejected Pope Francis' "program undermining the Deposit of Faith".

He has been particularly critical of the pope's attempt to make the Church more welcoming to the LGBT community and attempts by Francis to give lay people more responsibility in the Church and opposed a recent synod.

The dismissal followed a Vatican investigation earlier this year into the administration of the Tyler diocese, which Catholic media reports said included a review of his handling of financial affairs.

It was announced simultaneously by the Vatican and the U.S. Bishops Conference. Neither statement gave a reason.

There was no immediate response from Strickland. A recording on the diocese's telephone said they were closed for the weekend.

Strickland had become one of the most vocal standard bearers of the ultra-conservative wing of the U.S. Church and has a national following far beyond the small diocese of Tyler in eastern Texas.

Last August, the pope lamented what he called a "reactionary" Catholic Church in the United States, where he said political ideology had replaced faith in some cases.

Strickland is a strong supporter of former U.S. president Donald Trump and is seen as a hero by conservative U.S. Catholic media outlets that are aligned with Trump.

Last year, when the Vatican defrocked ultra-conservative U.S. anti-abortion priest Frank Pavone for "blasphemous" social media posts and disobedience to bishops, Strickland was one of the few American bishops to defend him publicly.

"The blasphemy is that this holy priest is canceled while an evil president promotes the denial of truth and the murder of the unborn at every turn, Vatican officials promote immorality and denial of the deposit of faith and priests promote gender confusion devastating lives...evil," Strickland wrote on the platform then known as Twitter.

The Vatican said Francis named the bishop of Austin, Texas, Joe Vasquez, as the interim administrator of the Tyler diocese.

(Reporting by Phil Pullella, writing by Alvise Armellini; Editing by Kirsten Donovan and Christina Fincher)