Gov. Luis Fortuno conceded defeat Wednesday to his main challenger after concluding there were not enough outstanding ballots to close the gap with his main challenger, Alejandro Garcia Padilla. The margin in Tuesday’s vote was less than 1 percent.

‘‘Now it’s time for us to come together as one people. The campaign is over,’’ Fortuno said in a news conference.

Fortuno, as a member of the pro-statehood New Progressive Party, said he was pleased that 61 percent of voters endorsed becoming a U.S. state, though critics said the two-part ballot was confusing to many and would not be enough to persuade the Congress to accept Puerto Rico into the union.

Fortuno, who is also a Republican, was a supporter of U.S. presidential candidate Mitt Romney and campaigned for him in Florida.

Garcia is part of the Popular Democratic Party, which wants Puerto Rico to remain semi-autonomous U.S. commonwealth.