India ordered its armed forces on Monday to help tackle surging new coronavirus infections, as nations including Britain, Germany and the United States pledged urgent medical aid to try to contain an emergency overwhelming the country's hospitals.

The situation in the world's second most populous country is "beyond heartbreaking", World Health Organization chief Tedros Adhanom Ghebreyesus said, adding that WHO is sending extra staff and supplies including oxygen concentrator devices.

In a meeting with India's Prime Minister Narendra Modi, the Chief of Defence Staff General Bipin Rawat said oxygen would be sent to hospitals from armed forces reserves and retired medical military personnel would join COVID-19 health facilities.