Matt Hancock has said he is "very worried" about the South African variant of Covid-19 and that the country should keep an "eagle eye" on it.
The new variant is deemed to be more transmissible than the UK one, which was already classed as being more prolific than the original coronavirus.
In order to stop the spread of the South African variant, flights to the UK from the country have already been banned.
"I am very worried about the new South African variant that we've seen." Mr Hancock told ITV News.
"That's why we've taken the very robust action to stop flights from South Africa.
"My concern is that it seems even more easy to transmit than the new variant we've seen here [in the UK].
"Obviously, it's been a huge challenge controlling the new variant that we've seen in the UK."
Only two cases of the new variant have been documented in the UK but officials are desperate to avoid more at a time when almost 55,000 new cases were confirmed on Sunday.
"Thankfully, there isn't evidence of very much spread of the South African variant here; we've seen two cases but we haven't seen any further cases since then but we've got to keep an eagle eye on this one because it is even harder to deal with than the UK variant."
ITV News Political Editor Robert Peston said that according to one of the government's scientific advisers, the reason for Mr Hancock's "worry" about the South African Covid-19 variant is that they are not as confident the vaccines will be as effective against it as they are for the UK's variant.
Scientists at Porton Down are currently researching this.