ROME, Italy, August 7, 2012 (LifeSiteNews.com) – Pope Benedict XVI is warning that the United States is facing threats of “unprecedented gravity” to religious freedom.

In a letter on behalf of the pope to Carl Anderson, Supreme Knight of the Knights of Columbus, Vatican Secretary of State Cardinal Tarcisio Bertone observed that “concerted efforts are being made to redefine and restrict the exercise of the right to religious freedom.”

The comments come as the U.S. bishops campaign for religious liberty in the face of attacks such as President Obama’s HHS mandate, which requires employers to cover contraceptives, sterilizations, and abortion-inducing drugs in their health insurance packages.

The bishops recently concluded their “fortnight for freedom” - two weeks of intensive “prayer, study, catechesis, and public action.” Shortly before launching the event, the bishops had reaffirmed their condemnation of the HHS mandate, nothing that the rule effectively punishes Catholic institutions for operating in the public sphere.

“Those deemed by HHS not to be ‘religious employers’ will be forced by government to violate their own teachings within their very own institutions. This is not only an injustice in itself, but it also undermines the effective proclamation of those teachings to the faithful and to the world,” they wrote.

Writing in advance of the Knights of Columbus’ annual Supreme Convention, which opened Tuesday in Anaheim, the prelate praised the Knights of Columbus for working “tirelessly to help the Catholic community recognize and respond to the unprecedented gravity of these new threats to the Church’s liberty and public moral witness.”

In his letter, Bertone quoted remarks by Pope Benedict in January in which he called on America’s bishops to “counter a reductive secularism which would delegitimize the Church’s participation in public debate about the issues which are determining the future of American society.”