CAIRO (AP) — The United Nations Children's Fund regional director says authorities in Yemen are making it "impossible" to deliver and distribute much-needed humanitarian aid to the country.

Geert Cappelaere says both Yemeni government and Houthi rebel authorities are being uncooperative. He tells The Associated Press in an interview from Yemen that impeding relief efforts could accelerate famine conditions.

Cappelaere says: "Respective authorities are not enabling us to do our work as fast as we should."

Yemen has been at war since March 2015 when Houthi rebels occupied northern regions and forced the government into exile. The Saudi-led coalition backing the exiled government accuses the Houthis of acting as Iran's proxy. The coalition has waged an extensive air campaign, causing thousands of deaths.