British Health Secretary Matt Hancock has said tougher border measures and enhanced contract tracing appeared to have restricted the spread of coronavirus variants from Brazil and South Africa.

Hancock said a roadmap to ease England's third national lockdown, due to be published on Monday, would need to allow time to analyse the data because the government is still concerned the variants could undermine the vaccine roll-out.

“There is evidence that the measures that we're taking, both the enhanced contact tracing and also the stricter measures at the border, there is evidence that these are working and that we've now got a much stronger vigilance in place,” Reuters quoted him as saying.