Because of pressure from mainland China the Republic of China hasn’t been allowed to join the UN. Only 15 nation recognize the country officially. The United States is not one of them even though we supply them militarily.
Now is the time for the United States, the European Union and other nations to accept Taiwan’s application to the United Nations. They might also consider an invite to join NATO. The Republic of China has been exemplary during the pandemic; helping other nations and keeping the spread of the virus relatively low on their own soil. Meanwhile the World Health Organization and the UN have been afraid to be critical of Communist China where the virus originated and where false information led to missteps in the handling of the pandemic by the rest of the world.