(Reuters) - A federal judge on Friday put same-sex marriages in Wisconsin on hold pending appeals of her ruling one week ago that the state's ban on gay nuptials is unconstitutional.

U.S. District Court Judge Barbara Crabb said she issued the stay at the request of Wisconsin officials who are appealing her decision and to avoid further confusion among county clerks who have issued hundreds of marriage licenses.

Crabb wrote in her opinion that she was required to follow the guidance of the U.S. Supreme Court and issue a stay, despite finding it difficult "after seeing the expressions of joy on the faces of so many newly wedded couples."

The judge's ruling last Friday, that Wisconsin's 2006 ban violated the U.S. Constitution, brought a rush to county clerks offices and a flurry of marriages. Crabb's order Friday did not address the status of those marriages.

According to Fair Wisconsin, an LGBT advocacy organization, 61 of the state's 72 county clerks have issued marriage licenses to same-sex couples since the ruling. A Reuters tally found that more than 500 gay couples have applied for or have been granted a marriage license in Wisconsin in the past week.

Crabb said she would have been inclined not to halt the marriages if not for a U.S. Supreme Court stay that stopped same-sex couples from marrying in Utah after a federal judge struck down that state's ban in December.

About 1,300 gay couples wed in Utah after the federal judge struck down the ban and before the Supreme Court stay. Since then, stays have been issued in several cases where judges have overturned state bans.

Wisconsin Attorney General J.B. Van Hollen, a Republican, said his office will appeal Crabb's decision to the U.S. Court of Appeals for the Seventh Circuit.

"By staying this ruling, she has confirmed that Wisconsin’s law regarding same-sex marriage remains in full force and effect," he said.

John Knight, an American Civil Liberties Union lawyer who brought the case on behalf of several same-sex couples, said they would seek a quick appeal in light of the stay.

With the stay in place in Wisconsin, same-sex marriage is legal in 19 states plus the District of Columbia. That number would jump sharply if federal court rulings striking down bans in several states are upheld on appeal.