The stepped-up diplomacy came as the conflict intensified between the nuclear-armed neighbours, with Pakistan launching counterattacks after India struck three of its air bases, according to officials.
The United States has close relations with India and immediately voiced solidarity after gunmen killed 26 tourists, mostly Hindu men, last month on the Indian-run side of divided Kashmir.
New Delhi blamed Islamabad for the attack and launched strikes against Pakistan as a response – although Islamabad has denied any involvement.
Rubio and the State Department have since called for de-escalation, mindful of the risks of the conflict spiralling into a devastating war.
But there have been signs of differing approaches within President Donald Trump’s young administration.
Vice President JD Vance, an outspoken critic of interventionist US foreign policy, said Thursday that while the United States wanted de-escalation, the conflict was “fundamentally none of our business.”
The United States has historically played a key behind-the-scenes role in mediating crises between India and Pakistan.
Since the Kashmir attack, Middle Eastern powers Iran and Saudi Arabia have also offered to play a role.
China, which has close ties with Pakistan including with supplies of military equipment, has called on the South Asian powers to show restraint.
