Aid officials say no food and little water have reached 64,000 Syrian refugees stuck in the desert since Jordan sealed its border last week in response to a suicide attack.

Abeer Etefa of the World Food Programme said Sunday that an extended closure "could put the lives of stranded Syrians at risk."

The refugees living in border tent camps have relied on deliveries of food and water from Jordanian territory, but Jordan says international agencies must find alternatives.

Jordan sealed the area after a cross-border suicide attack killed seven Jordanian troops last Tuesday.

Since then, only two water shipments have reached the refugees. Etefa says food was last distributed two weeks ago.

She says the WFP understands Jordan's security concerns, but hopes the border will eventually reopen.