(CNN) -- A federal judge on Friday temporarily blocked same-sex marriages in Wisconsin, pending appeals.

The same judge last week struck down the state's same-sex marriage ban. She did not stay her ruling then, allowing a number of same-sex marriages to proceed.

"After seeing the expressions of joy on the faces of so many newly wedded couples featured in media reports, I find it difficult to impose a stay on the event that is responsible for eliciting that emotion, even if the stay is only temporary. Same-sex couples have waited many years to receive equal treatment under the law, so it is understandable that they do not want to wait any longer," U.S. District Judge Barbara Crabb wrote in her decision Friday.

However, she added: "A federal district court is required to follow the guidance provided by the Supreme Court. Because I see no way to distinguish this case from Herbert, I conclude that I must stay any injunctive relief pending appeal."

Crabb was referring to a Supreme Court case in which same-sex marriages in Utah were put on hold.

Speaking about the judge's ruling Friday, Carl Tobias, a constitutional law professor at the University of Richmond, said that Crabb clearly felt constrained by the higher court.

"That leaves Wisconsin couples married in the last week in legal limbo, like couples in Utah and Michigan who married after the bans were invalidated and before stays were issued," he said.

Same-sex marriage is legal in 19 U.S states and the District of Columbia: California, Connecticut, Delaware, Hawaii, Illinois, Iowa, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, Vermont and Washington.

Worldwide, 16 other countries (and parts of Mexico) also have laws allowing same-sex marriage and domestic partnerships. Most of these are in Europe and South America.

Fast Facts: Same-sex marriage

CNN's AnneClaire Stapleton and Greg Botelho contributed to this report.