Starting Dec. 22, the U.S. could be on Israel's no-fly list due to high COVID infection rates. All travel from Israel to the U.S. will be banned, the Israeli government announced Sunday.

The Ministry of Health has recommended that the U.S., and nine other countries including Canada, be classified as "red list" countries. The decision now awaits final approval from the Knesset's Constitution, Law and Justice Committee.

Israeli citizens coming to Israel from the U.S. will have to go into full isolation, including those vaccinated or recovered. Non-Israeli citizens coming from the U.S. will not be allowed to enter Israel, officials said.

At the start of the weekly cabinet, Israel Prime Minister Naftali Bennett said the fact the country is in a "relatively good situation" is "not a coincidence." He attributed delaying the entry of the variant to Israel to travel bans. "What a pity that other countries did not do as we did," he said Sunday.

In addition to the U.S., Israel also will also move Belgium, Canada, Germany, Hungary, Italy, Morocco, Portugal, Switzerland and Turkey to the no-fly list this week on Dec. 22. Norway, France, Spain, Sweden and the UAE will be added to Israel's no-fly list at midnight Dec. 20.

There are 52 countries on Israel's red list.

-ABC News' Christine Theodorou

The U.K. reported a 48.59 percent single-day increase in confirmed omicron cases Sunday.

And across the U.K. in the last seven days, there's been a 51.9 percent increase in new COVID cases. Hospitalizations are up 8.1 percent during that period. However, there's been a 6.5 percent decrease in new deaths compared to the preceding seven days.

On Sunday, the British government reported 82,886 new COVID cases and 45 new deaths. The government also confirmed 12,133 new cases of the omicron variant.

London's mayor declared a major incident in the capital Sunday because of the serious threat of omicron. In an interview with the BBC on Sunday, he said that in the last 24 hours, "we're at almost 30,000 confirmed new cases, and in the last seven days almost 130,000 confirmed new cases."

He said he's worried about the impact the increases are already having on frontline emergency services in London, adding there are a record number of absences that will hamper their ability to respond to people who are unwell.

-ABC News' Christine Theodorou

"Saturday Night Live" won't have an audience and will limit its cast and crew at tonight's taping "out of an abundance of caution," the show announced, as New York sees a spike in COVID-19 cases.

"Due to the recent spike in the Omicron variant and out of an abundance of caution, there will be no live audience for tonight’s taping of 'Saturday Night Live' and the show will have limited cast and crew," tweeted the show, which films at 30 Rockefeller Plaza in Manhattan.

"The show continues to follow all government safety guidelines in addition to a rigorous testing protocol," it added.

Charli XCX was slated to be the musical guest but is no longer performing due to the limited crew, the singer announced on Twitter, saying she was "devastated and heartbroken."

Paul Rudd is the host of the episode, which is the last one of 2021.

The move comes as New York state broke its record for daily COVID-19 cases two days in a row. Several shows in New York City, from Broadway productions to the Rockettes, also have had to cancel performances due to COVID-19 cases.

-ABC News' Joshua Hoyos

Harvard University is shifting to remote learning for the first three weeks of January due to a "rapid" rise in COVID-19 cases locally, school officials announced Saturday.

"Please know that we do not take this step lightly," school leaders said in an update to students. "It is prompted by the rapid rise in COVID-19 cases locally and across the country, as well as the growing presence of the highly transmissible Omicron variant."

Only students with previous authorization will be allowed to remain on campus. Some programs, like essential in-person laboratory and patient-centered work, will continue as normal, the school said.

"We are planning a return to more robust on-campus activities later in January, public health conditions permitting," the school officials said.

Several universities, including Princeton, NYU and Cornell, have shifted final exams remote and canceled events in recent days due to spikes in COVID-19 cases.

-ABC News' Arielle Mitropoulos

The omicron variant appears to have a "growth advantage" over the delta variant, the World Health Organization said in a technical brief released Sunday.

"It is spreading faster than the delta variant in South Africa where delta circulation was low, but also appears to spread more quickly than the delta variant in other countries where the incidence of delta is high, such as in the United Kingdom," the WHO said in the brief, which was dated Friday. "Whether omicron's observed rapid growth rate in countries with high levels of population immunity is related to immune evasion, intrinsic increased transmissibility, or a combination of both remains uncertain. However, given the current available data, it is likely that omicron will outpace the delta variant where community transmission occurs."

Meanwhile, preliminary findings from South Africa suggest omicron may cause less severe illness than delta, and all cases of omicron reported in Europe to date have been mild or asymptomatic. But the WHO said "it remains unclear to what extent omicron may be inherently less virulent" and that "more data are needed to understand the severity profile."

The WHO also noted that "there are limited available data, and no peer-reviewed evidence, on vaccine efficacy or effectiveness to date for omicron." However, preliminary evidence, and the considerably altered antigenic profile of the variant's spike protein, suggests a reduction in vaccine efficacy against infection and transmission associated with omicron.

"There is some preliminary evidence that the incidence of reinfection has increased in South Africa, which may be associated with humoral (antibody-mediated) immune evasion," the WHO said.

The diagnostic accuracy of routinely used polymerase chain reaction (PCR) test and antigen-based rapid diagnostic test (Ag-RDT) assays does not appear to be influenced by omicron. Therapeutic interventions for the management of severe or critical COVID-19 symptoms associated with omicron are also expected to remain effective, according to the WHO.

"However, monoclonal antibodies will need to be tested individually, for their antigen binding and virus neutralization and these studies should be prioritized," the WHO added.

-ABC News' Christine Theodorou