VATICAN CITY (Reuters) - Pope Francis and Vatican officials on Thursday told U.S. President Barack Obama they were concerned about "religious freedom" in the United States, an apparent reference to the contraception mandate in Obama's health care plan.

Obama held nearly an hour of private talks with the pope and then the president and Secretary of State John Kerry held separate talks with Vatican Secretary of State Cardinal Pietro Parolin and other diplomats.

The talks included "discussion on questions of particular relevance for the Church" in the United States, including "the exercise of the rights to religious freedom, life and conscientious objection," a Vatican statement said.

Obama's 2010 healthcare law, widely opposed by Republicans, includes a provision that requires employers to cover the cost of contraception in their health insurance plans.

Catholic and other religious groups say the mandate forces them to support contraception and sterilization in violation of their religious beliefs or face steep fines.

The so-called contraception mandate has been the subject of more than 100 lawsuits across the United States.

Just this week the U.S. Supreme Court signaled it may allow corporations to mount religious objections to government action, possibly paving the way for companies to avoid covering employees' birth control as required under Obamacare.

During a 90-minute oral argument on Tuesday, the nine Supreme Court justices appeared ready to rule that certain for-profit entities have the same religious rights to object as individuals do.

There is an exception for religious institutions such as houses of worship that mainly serve and employ members of their own faith, but not schools, hospitals and charitable organizations employing people of all faiths.

The reference to "life" was reference to the Roman Catholic Church's opposition to abortion. Obama supports abortion rights.

The subject was raised when Obama met then-pope Benedict in 2009, when the president promised to do everything he could to reduce the number of abortions.

(Additional reporting by Steve Holland; Editing by Angus MacSwan)