Several hundred White House staffers have already been vaccinated against COVID-19 by the White House medical team, White House officials said, confirming a report from Axios.

The White House hopes to vaccinate all in-person staff in the next few weeks, officials said.

ABC News’ Molly Nagle contributed to this report

The United States is seeing improvements in COVID-19 infections and hospitalizations. In the last two weeks, the country's seven-day average of new COVID-19 cases has declined by 33.1%, according to ABC News' analysis of data compiled by The COVID Tracking Project, a volunteer-run effort to track the U.S. outbreak.

On Monday, Missouri reported the fewest number of new cases since September, while South Dakota reported the lowest number of new cases since July.

COVID-19 hospitalizations are also declining nationwide. The COVID Tracking Project said the number of people hospitalized with the disease in the U.S. is currently at its lowest since Dec. 14.

Hospitalizations are even trending down in California, which has more COVID-19 patients in hospitals than any other U.S. state.

ABC News’ Arielle Mitropoulous contributed to this report.

Colombian President Ivan Duque announced Tuesday that Defense Minister Carlos Holmes Trujilo died in the early morning hours from COVID-19 complications. He was 69.

"I can't express the pain that I have," Duque said in a statement while conveying his condolences to Trujilo's family.

Colombia has the third-highest number of confirmed COVID-19 cases in the Americas, behind the United States and Brazil, according to the World Health Organization.

ABC News’ Christine Theodorou contributed to this report.

Europe's longest land border, spanning more than 1,000 miles, has closed for the first time since World War II.

Sweden's temporary ban on entry from neighboring Norway went into effect Monday and will last until at least Feb. 14. The Swedish government has also extended an entry ban from the United Kingdom and Denmark until the same date.

The move comes amid concerns over a new, more contagious variant of the novel coronavirus that was first identified in the U.K. and has since spread to Norway's capital and the surrounding area.

On Saturday, shortly before Sweden announced the new travel ban, the Norwegian government imposed strict new lockdown measures for Oslo and nine neighboring municipalities due to an outbreak of the variant.

ABC News' Clark Bentson contributed to this report.

Dr. Anthony Fauci, the nation's leading infectious disease expert, spoke about the latest updates on the U.S. vaccine rollout during an interview Monday on ABC News Live.

Fauci, director of the National Institute of Allergy and Infectious Diseases, said that he believes the vaccine will be available to everyone beginning in April, but it won't be until the fall that everyone has actually gotten their shot in the arm.

"It will take several months-May, June, July, August- before you really get what I would consider the herd immunity level, which is an estimate, but I think it's a reasonable estimate, namely getting 70 to 85% of the population vaccinated," Fauci, who is also Biden's chief medical adviser, told ABC News Live.

Fauci said that the timeline is not considering a future approval of coronavirus vaccines developed by Johnson & Johnson and AstraZeneca.

"I think if the J&J or the [AstraZeneca] product comes through with an efficacy that's good enough to be able to be in the mix, that will be very helpful to get things done even sooner than we thought," he said.

Fauci also opened up about an incident where he was exposed to a powder substance that was in his mail last year. The powder was later deemed benign, but only after his security detail put on hazmat suits and sprayed him down.

"It frightened the heck out of my children when they found out about it and my wife too," he said. "I mean, I've decided I'm doing something that might be dangerous but that's it, I chose it. My children did not choose that."

Watch Fauci's full interview with ABC News Live at 7 p.m. and 9 p.m. ET Monday.