India's army chief will review security arrangements on Friday and visit the site of a deadly attack on tourists in Indian Kashmir earlier this week, an incident that has led to a fresh crisis with long-time rival and neighbour Pakistan.

The United States has said it stands with India and strongly condemns all acts of terrorism, calling for perpetrators of the "heinous" Pahalgam terror attack to be brought to justice.

Twenty-six men were killed and 17 were injured when suspected militants opened fire at tourists in India's Jammu and Kashmir territory, police said.