British Prime Minister Boris Johnson on Tuesday cancelled a scheduled India trip to deal with the worsening coronavirus crisis at home.
The post-Brexit trip had been framed by Downing Street as a shot in the arm for investment in the UK.
"The prime minister spoke to Prime Minister [Narendra] Modi this morning, to express his regret that he will be unable to visit India later this month as planned," a spokesman for 10 Downing Street said, blaming the fast-spreading strain of the virus.
Mr Johnson announced a new lockdown for England on Monday, explaining that urgent action was needed to prevent spiralling numbers of cases overwhelming health services.
The prime minister, according to Downing Street, told his Indian counterpart that "it was important for him to remain in the UK so he can focus on the domestic response to the virus".
Mr Johnson still hopes to visit India later in the first half of this year, before Mr Modi is due to attend a G7 summit in Britain later this year, the spokesman said.
The British leader was to be a guest at India's annual Republic Day celebrations on January 26, shortly after the UK left the EU's single market and as it seeks new trade deals around the world, particularly in Asia.
Announcing the trip last month, Mr Johnson said the visit would unveil "Global Britain" and help to deliver a "quantum leap" in relations with India, which was part of its former empire.