WASHINGTON — Supreme Court Justice Anthony Kennedy on Wednesday temporarily blocked an appeals court ruling that declared gay marriage legal in Idaho and Nevada.

Kennedy’s order came a little more than an hour Idaho filed an emergency request for an immediate stay and about 10 minutes before the state said that state and county officials would otherwise have been required to begin issuing marriage licenses to same-sex couples.

The order also applies to Nevada, where marriage licenses to same-sex couples were going to start to be issued later Wednesday.

The delay could last just a few days. Kennedy’s order requested a response from the plaintiffs involved in Idaho’s gay marriage lawsuit by the end of day Thursday.

The full court almost certainly would weigh in to extend the delay much beyond the weekend. That has been the justices’ practice in other cases in which a single justice initially blocked a ruling from taking effect.

The 9th U.S. Circuit Court of Appeals in San Francisco declared gay marriage legal in Idaho and Nevada on Tuesday. A day earlier, the Supreme Court let similar rulings from three other appeals courts become final and effectively raised to 30 the number of states where same-sex couples can marry, or soon will be able to do so.

Having allowed those other rulings to take effect without a full review by the Supreme Court, it would be surprising if the justices were to put the 9th circuit ruling on hold for any length of time.

The high court’s action Monday suggested that only an appellate ruling upholding a gay marriage ban would prompt the court to step in.