(Reuters) The governor of New Jersey declined to sign a measure into law on Thursday (May 11) that would have made it the first U.S. state to ban child marriage without exception.

Republican Chris Christie, a supporter of President Donald Trump, said such a ban would conflict with religious customs.

Underage marriage is widespread in the United States, where about 170,000 children were wed between 2000 and 2010 in 38 of the 50 states where data was available, according to activists.

Although age 18 is the minimum for marriage in most of the nation, every state has legal loopholes allowing children to wed.

The New Jersey bill would have prohibited any marriage of children under age 18.

Christie conditionally vetoed the measure, sending it back to the state legislature with proposed changes. He said it should have an exception so a judge can approve marriages for 16- and 17-year-olds.

“An exclusion without exceptions would violate the cultures and traditions of some communities in New Jersey based on religious traditions,” Christie said in a statement.

Opponents of the measure said exceptions should remain for marriages of young members of the military — 17-year-olds can enlist with parental consent — and pregnant teenagers.

The bill as it was already approved by both houses of the legislature would have made New Jersey the first state to outlaw child marriage altogether, according to Unchained At Last, a group that opposes arranged and forced marriages.

Most such marriages are underage girls married to older men, it said.

Communities and ethnic groups in the United States known to practice arranged or forced marriage include Orthodox Jews, Muslims, Mormons, Sikhs and Hmongs, according to Unchained At Last.

N.J. Assemblywoman Nancy Munoz, the bill’s main sponsor, said she was disappointed.

“It’s not an absolute veto, which is good,” she said.

The measure could become law if legislators send it back to the governor with his recommendations.

Studies have shown that child marriage is associated with mental health problems, poverty and increased high school drop-out rates.

The New Jersey bill prompted similar legislation in the states of California, Connecticut, Massachusetts, Missouri, New York, Pennsylvania and Texas.