Three security officers were killed in the attack by suspected Islamist militants on Pathankot base in northern Punjab state earlier Saturday. At least four attackers also died in shootouts with security forces.
The possible involvement of Pakistan-based militants threatens to derail talks between nuclear-armed rivals India and Pakistan, who have fought three wars since independence in 1947.
"The United States is committed to our strong partnership with the Indian government to combat terrorism," State Department spokesman John Kirby said in a statement, condemning the assault.
"We urge all countries in the region to work together to disrupt and dismantle terrorist networks and to bring to justice the perpetrators of this heinous act."