British Prime Minister Boris Johnson on Tuesday spoke to Prime Minister Narendra Modi to express his regret over not being able to visit India as planned for Republic Day on January 26 due to the growing crisis created by the new variant of coronavirus.

His call with Modi came a day after he addressed Britain in a televised address to plunge the country into a new stay-at-home lockdown as his medical chiefs warned that the National Health Service (NHS) was under threat of being overwhelmed by the rising infection rates.

Johnson has indicated that his India visit would take place during the first half of this year and before the G7 summit presided over by the UK, planned for later this year.

"The Prime Minister spoke to Prime Minister Modi this morning, to express his regret that he will be unable to visit India later this month as planned," a Downing Street spokesperson said.

"In light of the national lockdown announced last night, and the speed at which the new coronavirus variant is spreading, the Prime Minister said that it was important for him to remain in the UK so he can focus on the domestic response to the virus, the spokesperson said.

The two leaders underlined their "shared commitment" to the bilateral relationship, and to continuing to build on the close collaboration between our countries including in response to the pandemic.

The Prime Minister said that he hopes to be able to visit India in the first half of 2021, and ahead of the UK's G7 Summit that Prime Minister Modi is due to attend as a guest, the spokesperson said.