White House wants 'justice' done after Americans kidnapped, killed in Mexico

The White House on Tuesday denounced the kidnapping of four US citizens in Mexico, two of whom have been found dead, as "unacceptable," and said Washington would pursue justice for the victims.

"We're going to work closely with the Mexican government to ensure that justice is done in this case," White House national security spokesman John Kirby told reporters.

The four Americans crossed into Matamoros in northern Mexico, just opposite the US city of Brownsville, Texas, on Friday, according to the US Federal Bureau of Investigation.

They were fired upon by unidentified gunmen and taken hostage. Two were later found dead; of the other two, one is injured, according to Mexican authorities.

Kirby said the US was still learning about details of the incident from Mexican officials.

"Right now our focus is very squarely on these four Americans and the families that have been affected by the attack," he said.

"We don't have these four Americans back on home soil. And really that's what our focus is right now," he said.