As Zaventem Airport in Brussels, Belgium, partially reopens for limited flights today (April 3), American airline operator Delta has announced that all Brussels-bound flights from its flagship Atlanta terminal have been suspended, due to previous flight restrictions to the capital and "weakening demand" for flights following the terror attacks on 22 March.

Zaventem airport has been closed since the attacks took place, and there is currently no fixed reopening date or indication of when flights are due to resume. A total of 22 people were killed in the attacks, scores more were left critically injured.

Delta runs two services daily to Brussels, one from New York's John F Kennedy International airport and the other from Atlanta's Hartsfield-Jackson International Airport. In a statement posted on the air line's official website on 2 April, all Brussels-bound flights have been cancelled in the wake of the city's terror attacks, with a decrease in passengers boarding flights on the service, which runs daily from Zaventem.

"Delta remains committed to the Belgium market and will resume service between New York's JFK and Brussels once the airport provides clearance for international operations" reads the official statement on the Delta Airways website.

"Customers affected by the schedule change will be re-accommodated on alternative Delta services or flights operated by joint venture partners Air France and KLM."

It appeared that a limited flight schedule could resume on Sunday – less than two weeks after the attacks took place – but airport officials have already warned it could be "months" until full capacity is restored at the airport.

Three passenger flights will be scheduled for Sunday, airport CEO Arnaud Feist said during a joint news conference with security officials.

"The temporary arrangements won't be able to offer the level of comfort travellers are used to at Brussels Airport," Feist said. "Our main challenge is to rapidly return to normal capacity. We hope to have maximum capacity available at the start of the summer holidays, at the beginning of July."

Sunday's scheduled Belgium Airlines flights are to Faro, Portugal; Turin, Italy; and Athens, Greece. Brussels Airlines, the top carrier in Belgium, estimated the disruption has cost the company €5m ($5.7 million) a day.