The Reuters news agency says the US may stop refuelling aircrafts from the Saudi-Emirati coalition fighting in Yemen.
The US has been under pressure to limit its assistance in a war that's created a huge humanitarian crisis.
Meanwhile, Yemeni government forces backed by the coalition have launched a major offensive to retake the rebel-held city of Hodeidah.
The UN has warned that thousands of people have been trapped by the fighting.
Al Jazeera’s Emma Hayward reports.
