WASHINGTON - A US couple were among three missionaries killed in a gang attack in Haiti, family members and their organization said Friday, as the violence-stricken country endures months of worsening chaos and unrest.

Missions in Haiti Inc, an Oklahoma-based nonprofit founded in 2000, said Davy and Natalie Lloyd and a third missionary were shot and killed by gang members on Thursday evening.

The third victim was identified by several US media outlets as Jude Montis, the Haitian director of Missions in Haiti.

"Davy and Natalie and Jude were shot and killed by the gang about 9 o'clock this evening," Missions in Haiti said on its Facebook page. "We all are devastated."

Ben Baker, a member of the Missouri House of Representatives, confirmed that his daughter Natalie and son-in-law were dead.

"They were attacked by gangs this evening and were both killed," Baker said on Facebook.

Reacting to the attack, the White House called for the swift deployment of a Kenyan-led multinational force in Haiti.

"The security situation in Haiti cannot wait," said a National Security Council spokesperson, stressing that President Joe Biden had pledged to support the "expedited deployment" of the force in talks with Kenya's president on Thursday.

"Our hearts go out to the families of those killed as they experience unimaginable grief," the spokesperson added.

A spokesman for UN Secretary-General Antonio Guterres also expressed his condolences, calling it "just another example of the violence that spares no one in Haiti."

Missions in Haiti said on Facebook that the missionaries were "ambushed by a gang of 3 trucks full of guys."

"Davy was taken to the house tied up and beat," it said. "The gang then took our trucks and loaded everything up they wanted and left."

Members of another gang then arrived and "went into full attack mode," the group added.

Kenyan President William Ruto vowed during his visit to Washington that his country's upcoming deployment to Haiti would seek to crush the gangs that have ravaged the Western Hemisphere's poorest country.

The Biden administration has searched extensively for a country to take the lead on the mission to Haiti, but has ruled out sending in US forces, who have a long history of intervention in the Caribbean nation.