WASHINGTON — On Tuesday, President Joe Biden will take his most important moment on the international stage at United Nations General Assembly to defend his decision not to withdraw troops from Afghanistan and to seek to reestablish America‚Äôs alliances and position in the international community.

This speech will be his first as President at the meeting. Many world leaders have chosen to speak virtually, making it a far more interesting gathering than previous ones. Biden will also meet Tuesday in New York with Scott Morrison, the Australian prime minister, and Boris Johnson, the British prime minister back at the White House.

“America was back,” Biden stated during Monday’s meeting with U.N. secretary general. “We believe in the United Nations and its value because of the challenges we face today in ending Covid-19 and dealing with the gravest threat to humanity we’ve ever seen, which is the whole climate crisis we’re undergoing, that can only be met with global solutions. No one country can, no 10 countries can do it. “

But the summit comes at a time when some of the U.S.’ closest relationships have been strained following the chaotic troop withdrawal from Afghanistan, which left NATO allies complaining they were left out of the process and scrambling to evacuate their own people as the Taliban took control. Biden’s decision not to withdraw from Afghanistan has caused world leaders to question the U.S.’ global role. This is something Biden will address directly. A senior administration official stated that the president will “essentially drive home that ending the war on Afghanistan closed a chapter that focused on war and opened a chapter that focused on purposeful and effective, intensive American diplomacy” that involves working with allies, partners, and solving problems that cannot be solved using military force and that require cooperation from many nations around the globe. The official stated that Biden will address the Covid pandemic and climate change. He also plans to invest in clean infrastructure and trade with other countries.

Biden has also sparked tensions with France, one of America’s closest allies, following a security pact with Australia and the United Kingdom that would allow Australia to buy nuclear-powered submarines from the United States. France has reacted furiously to the deal, as it had originally planned to sell submarines to Australia.

France said last week it was recalling its ambassadors to the U.S. and Australia, with French officials saying its Indo-Pacific interests were undermined by the new agreement. The White House is currently arranging a phone call with French President Emmanuel Macron in order to discuss this issue. Jen Psaki, a press secretary, said Monday On the pandemic, Biden indicated that he would present a new strategy for vaccinating the globe and call upon other countries to do the same. According to an administration official, the U.S. will make a series announcements regarding further contributions it plans to making towards ending the pandemic.

The U.S. will hold a virtual Covid summit Wednesday in order to discuss its goals. It will focus on vaccines, treatments, and other technologies that can help to end the pandemic. He will call for an all hands-on-deck effort to end the pandemic faster than if things continue to evolve without the type of focused, sustained energy or effort required.

Still, Biden is expected to face pressure from world leaders, particularly those in lower-income countries, who have pleaded with the U.S. to do more to help the billions of people who have yet to get their first doses of a vaccine before providing people in the U.S. with third shots, which the Biden administration has been pushing for. The World Health Organization called for a “moratorium on boosters” and other international medical organizations criticized the U.S.’s plans to begin giving Americans a third dose. Only 20 percent of eligible people in lower-income countries have been at least partly vaccinated, compared to around 80 percent in some of the wealthiest countries, according to the WHO.

The U.S. has already given 140 million doses to nearly 90 countries and plans to give out another 200 million doses by the end of the year.

The U.S. sought to get out ahead of another area of pandemic-related criticism in the run-up to the meeting by announcing plans Monday to end a Trump-era travel ban that had kept foreign nationals from 33 countries, including many of those in Europe, from traveling to the U.S. as a precaution against Covid. On Monday, the administration announced that fully vaccinated foreign citizens will be allowed to travel to the U.S. if they have a positive Covid test and proof of vaccination. This year’s gathering will be reduced due to the pandemic. The U.N. has said that 83 leaders will make their remarks in person with the rest of the global leaders making recorded remarks. To be allowed to the debate hall, all delegates must have been vaccinated. Masks are not required except for those who are directly speaking at a meeting.

CORRECTION (Sept. 21, 2021, 9: 15 a.m. ET): A previous version of this article misspelled the first name of the French president. He is Emmanuel Macron and not Emanuel.

Image: Shannon PettypieceShannon Pettypiece

Shannon Pettypiece is the senior White House reporter for NBCNews.co