Puerto Rico's voters have overwhelmingly chosen for the territory to become the 51st US state in a non-binding referendum, the island's governor said.
Nearly half a million votes were cast for statehood, about 7,600 for free association/independence and nearly 6,700 for the current territorial status, according to preliminary results.
Voter turnout was just 23%, leading opponents to question the validity of a vote that several political parties had urged their supporters to boycott.
And the US Congress has final say in any changes to Puerto Rico's political status.
But that did not stop governor Ricardo Rossello from vowing to push ahead with his administration's quest to make the island the 51st US state and declaring that "Puerto Rico voted for statehood". He said he would create a commission to ensure that Congress validate the referendum's results.
"In any democracy, the expressed will of the majority that participates in the electoral processes always prevails," Mr Rossello said.
"It would be highly contradictory for Washington to demand democracy in other parts of the world, and not respond to the legitimate right to self-determination that was exercised today in the American territory of Puerto Rico."
It was the lowest level of participation in any election in Puerto Rico since 1967, according to Carlos Vargas Ramos, an associate with the Centre for Puerto Rican Studies at Hunter College in New York. He also said that even among voters who supported statehood, turnout was lower this year compared with the last referendum in 2012.
"Supporters of statehood did not seem enthusiastic about this plebiscite as they were five years ago," he said.
Puerto Rico's main opposition party rejected the pro-statehood result.
"The scant participation... sends a clear message," said Anibal Jose Torres, a party member. "The people rejected it by boycotting an inconsequential event."
The referendum coincides with the 100th anniversary of the United States granting US citizenship to Puerto Ricans, though they are barred from voting in presidential elections and have only one congressional representative with limited voting powers.
Among those hoping Puerto Rico will become a state is Jose Alvarez, a 61-year-old businessman.
"Now is the moment to do it," he said. "We've spent a lot of years working on a socioeconomic model that has not necessarily given us the answer."
Many believe the island's territorial status has contributed to its 10-year economic recession, which has prompted nearly half a million Puerto Ricans to flee to the US mainland and was largely sparked by decades of heavy borrowing and the elimination of federal tax incentives.
Those who oppose statehood worry the island will lose its cultural identity and warn that Puerto Rico will struggle even more financially because it will be forced to pay millions of dollars in federal taxes.
"The cost of statehood on the pocketbook of every citizen, every business, every industry will be devastating," Carlos Delegado, secretary of the opposition Popular Democratic Party, said.
"Whatever we might receive in additional federal funds will be cancelled by the amount of taxes the island will have to pay."
His party also has noted that the US Justice Department has not backed the referendum.
A department spokesman said that the agency has not reviewed or approved the ballot's language.
Federal officials in April rejected an original version, in part because it did not offer the territory's current status as an option.
The Rossello administration added it and sent the ballot back for review, but the department said it needed more time and asked that the vote be postponed, which it was not.
No clear majority emerged in the first three referendums on status, with voters almost evenly divided between statehood and the status quo.
During the last referendum in 2012, 54% said they wanted a status change, and 61% who answered a second question said they favoured statehood, but nearly half a million voters left that question blank, leading many to claim the results were not legitimate.