By Susan Heavey

WASHINGTON (Reuters) - The Obama administration's top health official on Friday took the debate over whether healthcare coverage should include contraceptives to the campus of a Catholic university that has been deeply divided over the administration's policy.

U.S. Health Secretary Kathleen Sebelius, in a speech at Georgetown University a few miles from the White House, praised the new U.S. healthcare law requiring coverage and called for "conversation and compromise."

Sebelius has become the public face for the contraception rules issued earlier this year that have provoked fierce backlash from Catholic Church officials, political conservatives and anti-abortion advocates. The issue has become a point of debate in the U.S. presidential race.

Sebelius' presence on campus drew fire in recent days from church leaders and religious groups, who criticized her selection. Some of them called on Georgetown to rescind her speaking invitation.

About 20 protesters lined a campus entrance amid beefed up security, and a heckler, who interrupted Sebelius by calling her a "baby killer," was led away by campus police.

In her speech, Sebelius acknowledged the deep, continuing debate over what she called "the intersection of our nation's long tradition of religious freedom with policy decisions that affect the general public."

Such contentious policy debates, however, are the strength of the American system, she said. She called on the graduating public policy students to take on tough debates but also to "see issues from other points of view, and in the end, follow your own moral compass."

"Our system is messier, slower, more frustrating and far better. It requires conversations that can be painful and it almost always ends in compromise," she told about 1,200 students and family members.

"But it's through this process of conversation and compromise that we move forward, together, step by step, towards a more perfect union," she said.

In a letter earlier this week, the Archdiocese of Washington criticized the university for ignoring what it said was the administration's "direct challenge to religious liberty."

The Becket Fund, a religious legal advocacy firm that is handling several lawsuits against the White House over the contraceptives issue, also started an online petition that drew more than 10,000 signatures.

Students of Georgetown's Public Policy Institute elected Sebelius as their speaker for an awards ceremony following the commencement while students and faculty wrote letters supporting her attendance as a policy expert. Georgetown President John DeGioia said Sebelius' invitation was not an endorsement of her views.

Sebelius has ties to the university - her husband and one of her sons are Georgetown graduates.

President Barack Obama's 2010 healthcare overhaul aims to expand health insurance coverage and calls for employers to cover a wide range of preventive care, including contraception.

Churches are exempt but other religious groups, including universities, are not. Amid church protests, the administration later said health insurance companies and not the groups themselves could cover birth control.

The coverage requirement goes into effect in August but the administration is allowing a one-year grace period that it hopes will enable compromise with employers who object to the plan. Earlier this year, Georgetown's DeGioia said the school will take the extension.

Obama's healthcare plan has been a mixed blessing for religious leaders, who have embraced its extension of healthcare coverage for the millions of uninsured Americans.

Sebelius told the graduates about her "opportunity to help implement legislation that is finally, after seven decades of failed debate, ensuring that all Americans have access to affordable health coverage."

That line drew heavy applause.

(Reporting by Susan Heavey; Editing by Marilyn W. Thompson and Jim Loney)