The U.S. topped 25 million confirmed coronavirus cases Sunday, over one-quarter of the world’s caseload, which is approaching 100 million. The U.S. has recorded over 419,000 deaths. President Joe Biden is expected to reinstate travel restrictions from Brazil, Britain and much of Europe, as well as impose a new ban on non-U.S. citizens traveling from South Africa, where health officials say a more transmissible variant is behind a devastating surge. Top infectious disease expert Anthony Fauci said over the weekend there are concerns existing COVID vaccines could become less effective against new coronavirus variants. British Prime Minister Boris Johnson said for the first time Friday the U.K. variant may be not just more infectious, but up to 30% more deadly, as well. Britain’s chief scientific adviser cautioned that evidence of the claim “is not yet strong” and that more research is needed.

President Biden and members of his team warned over the weekend the coming weeks and months will be tough. Biden addressed U.S. mayors at a conference Sunday.

President Joe Biden: “The brutal truth is that things are going to get worse the next several months before they get better. We didn’t get into this mess overnight. It’s going to take time for us to turn things around.”