Haiti has declined to join the Dominican Republic in reopening a crucial commercial border crossing, which has led to a diplomatic crisis over the construction of a canal on Haitian soil.

The Dominican President, Luis Abinader, had closed all borders, including the northern Dominican city of Dajabon, for nearly a month to protest the construction of the canal, which he believes violates a treaty and threatens the water supply of Dominican farmers.

However, Haiti maintains that it has the right to build the canal, which is urgently needed due to a drought.

On Wednesday, the Dominican government partially reopened the borders, including the one at Dajabon, which is home to a key market for commerce between the two countries.

However, the government only allowed limited trade, and a ban on Haitians entering the Dominican Republic for work, school, tourism or medical issues remained in place. The government also maintained its ban on issuing visas to Haitian citizens.

On the other hand, Haiti refused to follow suit at its gate in the nearby community of Ouanaminthe, and its government did not immediately state a reason.

But Moïse Charles Pierre, a delegate for Haiti’s northeast region, told The Associated Press that the Dominican side needed to apologize and resume full border operations.

Meanwhile, the two other border gates at Elias Pina and Independencia have opened on both sides.

At an Organization of American States meeting in Washington, the dispute over the canal took center stage on Thursday, with sharp exchanges between Roberto Álvarez, foreign affairs minister for the Dominican Republic, and Léon Charles, Haiti’s permanent representative to the OAS.

During the meeting, OAS Secretary General Luis Almagro offered to send a technical team specialized in water resources and legal issues to examine the site and offered to facilitate a meeting between both sides.

The canal in Haiti aims to divert water from the Massacre River that runs along the border on the island of Hispaniola, which both countries share. Haiti’s government has stated that farmers urgently need the water to quench a drought that has killed crops in the region. Abinader has said that the construction of the canal violates a 1929 treaty and would affect local farmers and nearby wetlands.

On Thursday, former Haitian prime minister and presidential candidate Claude Joseph issued a statement rejecting allegations by a Dominican ambassador that he had ordered work on the canal to provoke a crisis with the Dominican Republic. However, Joseph insisted that Haiti has the right to build the canal.