Benin has blocked export of Niger crude from its port after the landlocked West African nation refused to open its land borders for goods coming from Benin.

At least three vessels set to transport the first shipment of crude from Niger was prevented from docking, according to a port official. 

“If you want to load your oil in our waters, you can’t view Benin as an enemy and at the same time expect your oil to cross our territory,” President Patrice Talon said on Wednesday. “We’re open to working with Niger. They’re the ones that refuse to allow trucks to cross Benin. They refuse to let the port of Cotonou serve them.”

Niger is expected to export its first shipment of crude this month, part of a $400 million commodity-backed loan with state-owned China National Petroleum Corporation.

Under the loan agreement, Niger will send oil to China over 12 months as payment with a 7% interest rate. CNPC has already built a 1,200-mile pipeline to move oil from Niger to neighboring Benin, part of a $4.6 billion investment in Niger’s petroleum industry. Niger was expected to start shipping 90,000 barrels per day this month, and increase to 110,000 barrels per day once the pipeline is fully operational.

CNPC couldn’t immediately be reached for comment. A spokesman for Niger’s junta declined to comment when reached by text. 

The Economic Community of West African States closed land and air borders with Niger in a bid to convince the military junta which took power in a July coup to restore civilian rule. The sanctions were lifted earlier this year but Niger continues to keep its land borders with Benin closed.

“Benin immediately implemented measures to lift sanctions and open our borders,” Talon said. “It’s unfortunate to note that since then Niger hasn’t done the same.”

Oil production is expected to spur Niger’s economic growth to more than 11% this year, making it the fastest growing in sub-Saharan Africa, according to the International Monetary Fund.