The United States says North Korea is rejecting shipments of U.S. food aid.

State Department spokesman Robert Wood told reporters Wednesday that Pyongyang recently notified Washington that it no longer wants U.S. food assistance, giving no reasons for its rejection.

Wood said Washington is “very concerned” about the North’s decision as it comes when the North faces chronic food shortages and depends on foreign aid to feed its people.

According to Wood, the United States has delivered 169-thousand metric tons of food to the communist state since the beginning of last year out of a total 500-thousand metric tons promised. The last shipment of five-thousand metric tons arrived in late January.

The North’s notification comes amid heightened tension between Washington and Pyongyang over the North’s plans to launch a rocket.