US 'reviewing' support for Saudi coalition in Yemen
Scores of people died and more than 500 wounded in air strikes on a community hall in Sanaa on Saturday where mourners had gathered, with Houthi rebels laying blame on the coalition force.
It has denied responsibility for the attack, but support from Riyadh's key ally has wavered.
"We are deeply disturbed by reports of today's air strike on a funeral hall in Yemen, which, if confirmed, would continue the troubling series of attacks striking Yemeni civilians," White House National Security Council spokesman Ned Price said in a statement.
"US security cooperation with Saudi Arabia is not a blank check," he added.
More than 140 people were killed and 525 injured when the funeral ceremony was bombed, United Nations officials said.
People had gathered to mourn the death of the father of rebel interior minister Jalal al-Rowaishan.
The UN has called for an immediate investigation.
"This horrendous and heinous attack displayed an utter disregard for human life," said UN Under-Secretary General for Humanitarian Affairs Stepehn O'Brien.
The coalition has come under increasing scrutiny in recent months over the civilian death toll in its aerial campaign.
In September 2015, a suspected coalition air strike killed 131 civilians at a wedding near the port city of Mokha.
And in March this year, Saudi-led air strikes killed at least 119 people in the northern rebel-held province of Hajja.
In August, the US significantly reduced the number of military personnel coordinating support for the Arab coalition campaign.
Meanwhile, US aerial tankers continue to refuel Saudi jets.