Pope Francis has backed a doctrinal report drawn up under his predecessor Benedict XVI that accuses the largest group of nuns in the United States of holding "radical feminist" views.

The new pope has "reaffirmed the findings of the assessment and the program of reform" for the Leadership Conference of Women Religious (LCWR), which represents around 45,000 US nuns and is known for its social work, the Vatican said on Monday.

The statement said the head of the Vatican's Congregation for the Doctrine of the Faith, Ludwig Mueller, met with representatives of the LCWR in the Vatican on Monday in an attempt to smooth over differences.

Mr Mueller thanked the group for its work in "many schools, hospitals, and institutions of support for the poor" in the US, the statement said.

But he also emphasised the need for the group to cooperate with US bishops and said LCWR was legally "under the direction of the Holy See".

The Vatican report issued in 2012 following a three-year investigation points to "serious doctrinal problems" and "unacceptable positions".

The Vatican appointed the Archbishop of Seattle, Peter Sartain, to ensure the group toe the line.

The report accuses LCWR members of "dissent" with Church teachings against homosexuality and says they were pursuing "radical feminist themes".

It condemns LCWR for being "silent on the right to life from conception to natural death".

The report also says a position stated by LCWR in 1977 against the ordination of priests as a male prerogative "has never been corrected".

AFP