Previous tweets from President Joe Biden and Vice President Kamala Harris are igniting accusations of hypocrisy after the administration announced a travel ban in response to a new COVID-19 variant.

A World Health Organization panel convened on Friday to assess the potential of the SARS-CoV-2 variant "omicron," formerly known as B.1.1.529. The WHO classified the latest variant as a "highly transmissible virus of concern," which is also what the health agency previously named the delta variant as.

"We don't know very much about this yet. What we do know is that this variant has a large number of mutations. And the concern is when you have so many mutations it can have an impact on how the virus behaves," said Maria van Kerkhove, an epidemiologist and WHO technical lead on COVID-19. "This is one to watch, I would say we have concern. But I think you would want us to have concern."

The Botswana government said there were four cases of the omicron variant reported on Nov. 22, and that all four patients were fully vaccinated for COVID-19.

MEDIA RELEASE\n#LetsDefeatCOVID19Together\n#AReFenyengCOVID19Mmogo pic.twitter.com/LVMbmtLQx4

— Botswana Government (@Botswana Government) 1637849790

Cases of the omicron variant have already been identified in Belgium, the U.K., Germany, the Czech Republic, Hong Kong, and Israel.

The WHO cautioned against countries implementing travel bans.

"At this point, implementing travel measures is being cautioned against," WHO spokesman Christian Lindmeier said during a United Nations briefing in Geneva. "The WHO recommends that countries continue to apply a risk-based and scientific approach when implementing travel measures."

Dr. Michael Ryan — the head of emergencies at the WHO — warned against "knee-jerk responses."

"We've seen in the past, the minute there's any kind of mention of any kind of variation and everyone is closing borders and restricting travel," Ryan said. "It's really important that we remain open, and stay focused."

Despite the WHO recommendation, several countries implemented travel restrictions on African nations, including Australia, Canada, the United States, the United Kingdom, and all 27 member states of the European Union.

The South African foreign ministry reacted to the travel bans by saying the country was being punished for being one of the first nations to identify the new COVID-19 variant. South Africa first reported cases of B.1.1.529 to the WHO on Nov. 24.

"This latest round of travel bans is akin to punishing South Africa for its advanced genomic sequencing and the ability to detect new variants quicker," the Ministry of International Relations and Cooperation said in a statement. "Excellent science should be applauded and not punished."

The White House issued a statement on the travel ban, "The United States Government, including the Centers for Disease Control and Prevention (CDC), within the Department of Health and Human Services, has reexamined its policies on international travel and concluded that further measures are required to protect the public health from travelers entering the United States."

Biden's travel ban goes into effect on Nov. 29, 2021.

The official Twitter account for President Biden issued a statement:

The @WHO has identified a new COVID variant which is spreading through Southern Africa. As a precautionary measure until we have more information, I am ordering air travel restrictions from South Africa and seven other countries. As we move forward, we will continue to be guided by what the science and my medical team advises. For now the best way to strengthen your protection if you're already vaccinated is to get a booster shot, immediately. For those not yet fully vaccinated: get vaccinated today. For the world community: this news is a reminder that this pandemic will not end until we have global vaccinations. The U.S. has already donated more vaccines to other countries than every other country combined. It is time for other countries to match our speed and generosity.

The @WHO has identified a new COVID variant which is spreading through Southern Africa. As a precautionary measure until we have more information, I am ordering air travel restrictions from South Africa and seven other countries.

— President Biden (@President Biden) 1637955501

For the world community: this news is a reminder that this pandemic will not end until we have global vaccinations. The U.S. has already donated more vaccines to other countries than every other country combined. It is time for other countries to match our speed and generosity.

— President Biden (@President Biden) 1637955502

However, many commentators resurfaced old tweets by Biden that are deemed as hypocritical.

On Jan. 31, 2020, then-President Donald Trump declared a public health emergency in response to the global COVID-19 outbreak and temporarily suspended the entry of travelers from China. A day later, then-candidate Biden responded by saying Trump was xenophobic, "We are in the midst of a crisis with the coronavirus. We need to lead the way with science — not Donald Trump's record of hysteria, xenophobia, and fear-mongering. He is the worst possible person to lead our country through a global health emergency."

We are in the midst of a crisis with the coronavirus. We need to lead the way with science \u2014 not Donald Trump\u2019s record of hysteria, xenophobia, and fear-mongering. He is the worst possible person to lead our country through a global health emergency.

— Joe Biden (@Joe Biden) 1580594460

On March 11, 2020, then-President Trump suspended travel from Europe in an attempt to slow the spread of coronavirus. The next day, Biden said travel bans would not stop the spread of COVID-19, "A wall will not stop the coronavirus. Banning all travel from Europe — or any other part of the world — will not stop it. This disease could impact every nation and any person on the planet — and we need a plan to combat it."

A wall will not stop the coronavirus.\n\nBanning all travel from Europe \u2014 or any other part of the world \u2014 will not stop it.\n\nThis disease could impact every nation and any person on the planet \u2014 and we need a plan to combat it.

— Joe Biden (@Joe Biden) 1584057900

In January 2020, when Trump added new immigration restrictions on six African and Asian countries — Nigeria, Myanmar, Kyrgyzstan, Eritrea, Sudan, and Tanzania — Democrats claimed the policy was "driven by hate."

Biden tweeted, "Trump further diminished the U.S. in the eyes of the world by expanding his travel ban. This new 'African Ban,' is designed to make it harder for black and brown people to immigrate to the United States. It's a disgrace, and we cannot let him succeed."

Trump further diminished the U.S. in the eyes of the world by expanding his travel ban. This new \u201cAfrican Ban,\u201d is designed to make it harder for black and brown people to immigrate to the United States. It\u2019s a disgrace, and we cannot let him succeed.https://medium.com/@JoeBiden/statement-from-vice-president-joe-biden-on-donald-trumps-expanded-travel-ban-17ac0ee039b9\u00a0\u2026

— Joe Biden (@Joe Biden) 1580613364

Kamala Harris responded by saying, "Trump's extended un-American travel ban undermines our nation's core values. It is clearly driven by hate, not security."

Trump\u2019s extended un-American travel ban undermines our nation\u2019s core values. It is clearly driven by hate, not security.https://www.npr.org/2020/01/31/801615610/trump-administration-to-curb-immigrants-from-6-nations-including-nigeria\u00a0\u2026

— Kamala Harris (@Kamala Harris) 1580595361

At the time, House Speaker Nancy Pelosi issued a statement, claiming Trump's immigration policy "undermined our Constitution" and was "bigoted."

The Trump Administration's expansion of its outrageous, un-American travel ban threatens our security, our values and the rule of law. The sweeping rule, barring more than 350 million individuals from predominantly African nations from traveling to the United States, is discrimination disguised as policy.

America's strength has always been as a beacon of hope and opportunity for people around the world, whose dreams and aspirations have enriched our nation and made America more American. With this latest callous decision, the President has doubled down on his cruelty and further undermined our global leadership, our Constitution and our proud heritage as a nation of immigrants.

In the Congress and in the Courts, House Democrats will continue to oppose the Administration's dangerous anti-immigrant agenda. In the coming weeks, the House Judiciary Committee will mark-up and bring to the Floor the NO BAN Act to prohibit religious discrimination in our immigration system and limit the President's ability to impose such biased and bigoted restrictions. We will never allow hatred or bigotry to define our nation or destroy our values.