Republican presidential candidate Ben Carson officially backed Puerto Rican statehood in a speech on the island on Sunday.

“In a Carson administration, I will leave no stone unturned in my efforts to secure this important step in Puerto Rico’s history – establishing Estado 51,” Carson said, according to CNN.

Carson said he viewed the issue of statehood as “settled,” the news network added, referring to a referendum to join the union backed by a majority of Puerto Rican citizens in 2012.

“Mis hermanos Americanos,” Carson reportedly said, “my campaign is built around the premise of ‘We the people,’ and through such lens, I view the statehood question in Puerto Rico as settled.”

The Carson campaign estimated that 3,500 people attended the rally for the pro-statehood New Progressive Party.

Other Republican candidates for president, such as former Florida Gov. Jeb Bush and Sen. Marco Rubio (R-Fla.), support Puerto Rican statehood, provided the island's residents vote to approve it.

Democratic front-runner Hillary Clinton has not endorsed statehood for the U.S. commonwealth, but has supported economic relief measures for the island in the past.