LONDON - British Health Secretary Matt Hancock 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.

However he told Sky News that the initial signs were encouraging.

"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."

Prime Minister Boris Johnson will set out the roadmap on Monday, having got off to a faster than expected start with Britain's vaccine roll-out programme.

"It is very important to see the impact of steps that we're taking," Hancock said of the next steps. "We want to set out a roadmap which gives people guidance in terms of how we think we'll be able to do this. We also absolutely will be vigilant to the data on the way.

"We've currently seen other new variants that thankfully there's very, very, very few of in this country now, but we've got to protect against them."