Ricardo Rossello declared, after the island voted to become the 51st US state in a non-binding referendum.
It did not act on the previous referendum's result, which was the first time ever a majority of valid votes were cast for statehood in the former Spanish colony.
Under the current system, Puerto Rico's 3.5 million American citizens do not pay federal taxes, vote in presidential elections or receive proportionate federal funding on programs like the Medicaid health insurance system for the poor. But Gov. Ricardo Rossello said the vote sends a clear message to Congress.
Becoming the 51st US state in any case depends on the US Congress, where there is little enthusiasm for the move.
"We will go before worldwide forums to defend the argument of the importance of Puerto Rico being the first Hispanic state in the United States", Rossello said, appearing with his wife Beatriz Areizaga Garcia in the northeastern city of Guaynabo.
"Eight out of 10 voters went to the beach, went to the river, went to go eat, went to go hang out, went to church, but they sure didn't go out to vote", said opposition party leader Héctor Ferrer at a San Juan press conference according to NBC News. The governor announced that the US territory overwhelmingly chose statehood on Sunday in a non-binding referendum held amid a deep economic crisis that has sparked an exodus of islanders to the USA mainland.
US Rep. Nydia Velázquez (D-NY), who was born in Puerto Rico, dismissed the process as a "dog and pony show" and said the low turnout means the results can't be trusted.
Puerto Ricans have been U.S. citizens since 1917, however, as residents of a commonwealth territory rather than a state they can't vote for president in the USA general election.
The validity of the referendum, which came amid an economic crisis that has forced the island into bankruptcy and caused the ailing government to install grim austerity measures, has been challenged by opposition parties due to a low turnout.More news: OECD Says Global Growth "Better But Not Good Enough"
Almost half of the island's 3.4 million people live in poverty, and unemployment is 12.4 percent, compared with 4.3 percent on the US mainland.
"The bad side of it is that we are not a full part of the United States", he told NPR's Greg Allen and Marisa Peñaloza earlier this year.
Nevertheless, the final say regarding Puerto Rican statehood lies with Congress despite the referendum's outcome.
Governor Ricardo Rossello, right, and Congresswoman representing Puerto Rico Jennifer Gonzalez celebrate the results of a referendum on the status of the island, at the New Progressive Party headquarters in San Juan, Puerto Rico, Sunday, June 11, 2017.
Puerto Rico came under United States control in 1898 after the Spanish-American War.
"We have been a colony for 500 years, and we have had USA citizenship for 100 years, but it's been a second class one", Rossello said.
Sunday's ballot was a revised version after the Department of Justice wrote to Rosello in April saying the referendum ballot at the time incorrectly omitted Puerto Rico's current commonwealth status as a ballot option, offering only statehood or free association/independence. This is in stark contrast to the last plebiscite held in 2012 - in which 1,363,854 people, or 78.19 percent of registered voters, cast a ballot.