Updated

Utah is going straight to the U.S. Supreme Court to appeal a federal appeals court's ruling that gay couples have a constitutional right to marry, the state attorney general's office announced Wednesday.

The state opted to challenge the decision with the nation's highest court rather than request a review from the entire 10th U.S. Circuit Court of Appeals in Denver. That option is now off the table, no matter what the high court decides.

Utah Attorney General Sean Reyes' office said in a statement the appeal will be filed in the coming weeks. "Attorney General Reyes has a sworn duty to defend the laws of our state," the statement said.

The Supreme Court is under no obligation to hear the appeal, and there is no deadline to make a decision, said William Eskridge, a law professor at Yale University. The three-judge 10th Circuit panel put its June 25 ruling on hold pending an appeal.

The Utah case is certain to pique the Supreme Court's interest, but the justices usually look for cases that involve split rulings from federal appeals courts, said Douglas NeJaime, a University of California-Irvine law professor. The court may wait and take up the matter after one or more of the five other appeals courts with pending gay marriage cases has ruled.

The 4th U.S. Circuit Court of Appeals heard arguments about Virginia's ban in early May, and a ruling is expected soon. Arguments are scheduled for August and September in two different courts for cases out of Michigan, Ohio, Kentucky, Tennessee, Nevada and Idaho.

Eskridge doesn't expect a quick decision from the high court.

"Why make a decision on the Utah case until they see what the other circuits are going to do?" Eskridge said.