JUNEAU, Alaska — Alaska Gov. Mike Dunleavy on Wednesday vetoed a bipartisan bill that would have forced insurance companies to cover up to a year’s supply of birth control at a time, a measure that supporters said was especially important in providing access in rural areas.

In an emailed statement, Dunleavy spokesperson Jeff Turner said the Republican governor vetoed the bill because “contraceptives are widely available, and compelling insurance companies to provide mandatory coverage for a year is bad policy.”

The measure overwhelmingly passed the state Legislature this year: 29-11 in the Republican-controlled House and 16-3 in the Senate, which has bipartisan leadership. It was not opposed by insurance companies, supporters noted.

“Governor Dunleavy’s veto of HB 17, after eight years of tireless effort, overwhelming community support, and positive collaboration with the insurance companies, is deeply disappointing,” said Democratic Rep. Ashley Carrick, the bill’s sponsor. “There is simply no justifiable reason to veto a bill that would ensure every person in Alaska, no matter where they live, has access to essential medication, like birth control.”

Supporters of the bill said the veto would keep barriers in place that make it difficult to access birth control in much of the state, including villages only accessible by plane, and for Alaska patients on Medicaid, which limits the supply of birth control pills to one month at a time.

“Those who live outside of our urban centers — either year-round or seasonally — deserve the same access to birth control as those who live near a pharmacy,” Rose O’Hara-Jolley, Alaska state director for Planned Parenthood Alliance Advocates, said in a news release.

Supporters also said improving access to birth control would reduce the number of unwanted pregnancies and abortions.