The island of Santa Rosa sits in the Amazon River between Colombia and Peru, with the government in Lima recently naming it a federal district.
Colombian President Gustavo Petro has accused the neighbouring country of Peru of annexing a disputed island on the Amazon River, resuscitating a longstanding disagreement between the two nations.
In a social media post on Tuesday, Petro said that Peru had acted to “unilaterally” assert control over the small island of Santa Rosa in a recent congressional vote.
“The Peruvian government has just appropriated it by law,” Petro wrote on the social media platform X.
He added that Peru’s actions could block the Colombian city of Leticia from accessing the Amazon River. “Our government will resort to diplomacy to defend our national sovereignty.”
Petro’s comments appeared to be a response to a vote in June, whereby Peru’s Congress designated the island of Santa Rosa a district in its Loreto province.
Who controls the island has been a subject of debate between Peru and Colombia for nearly a century.
Peru has claimed ownership based on treaties from 1922 and 1929, and it has administered Santa Rosa for decades.
But Colombia maintains that the island of Santa Rosa had not emerged from the Amazon River at the time of the treaties and therefore is not subject to them.
It has also argued that the treaties set the boundary between the two countries at the deepest point of the Amazon River, and that islands like Santa Rosa have emerged on the Colombian side of that dividing line.
“Islands have appeared north of the current deepest line, and the Peruvian government has just appropriated them by law and placed the capital of a municipality on land that, by treaty, should belong to Colombia,” Petro wrote.
He warned that Peru’s claims to Santa Rosa could inhibit travel and trade to nearby Leticia, which boasts a population of nearly 60,000.
“This unilateral action”, Petro wrote on Tuesday, “could make Leticia disappear as an Amazonian port, taking away its commercial life”.
Petro said he would hold celebrations commemorating Colombian independence from Spain in Leticia on Thursday, framing the island’s status as a symbol of national sovereignty.
The Colombian Ministry of Foreign Affairs also said in a social media post that it would push for further diplomacy in determining the nationality of newly emerged islands.
“For years, Colombia has maintained the need to carry out bilateral work for the allocation of islands,” the ministry wrote. Colombia, it added, “has reiterated the position that ‘Santa Rosa Island’ has not been allocated to Peru”.
The Amazon River is one of the longest waterways in the world, with the most water discharged of any river.
But those powerful currents deposit and rearrange sediment throughout the river basin, forming – and sometimes erasing – islands.
Santa Rosa is one of those newer islands. The land now contains forest and farmland, as well as the village of Santa Rosa de Yavari.
That town is home to a population of fewer than 1,000 people, according to Peru’s latest census, and is largely reliant on tourism, based on its proximity to the Amazon.
The Peruvian government has argued that making Santa Rosa a district was necessary to ensure it received federal funds and could collect taxes.
“Peru is complying firmly with its obligations under international law and with valid bilateral treaties,” the Peruvian government said in a statement.
