U.S. President Donald Trump said Wednesday (September 23) he might not approve stricter regulatory standards for a COVID-19 vaccine. Trump has repeatedly said a COVID-19 vaccine could be ready for distribution by the November 3 presidential election. The Washington Post reported on Tuesday the U.S. Food and Drug Administration would issue new emergency authorization guidance for the vaccine to boost transparency and public trust. That comes as health experts grow increasingly concerned that the Trump administration might be interfering in the approval process to rush the vaccine out. But on Wednesday Trump questioned why a vaccine would need to be delayed -- and said such a proposal by the FDA would appear to be politically-driven. "It sounded to me, it sounded extremely political. Why would they do this when we come back with these great results -- and I think you will have those great results -- Why would we be delaying it?" Few vaccine developers are expected to have definitive trial results before the election. Pfizer had been the exception, although its timeline may also slip with new FDA guidelines. Moderna has said its unlikely to have data by October, while AstraZeneca's trials have been halted as investigators try to determine whether one participant's unexplained neurological problem was caused by the vaccine. FDA head Stephen Hahn did not directly address the Washington Post report when testifying before a Senate hearing on the health crisis earlier on Wednesday. But he did say regulators would likely provide more information on the emergency use authorization process. At the same hearing, U.S. Centers for Disease Control and Prevention head Robert Redfield said he expects about 700 million doses of vaccines to be available by late March or April, enough for 350 million people.