US Vice President Kamala Harris and House Speaker Nancy Pelosi look at each other as US President Joe Biden addresses a joint session of Congress, April 28, 2021, in the House Chamber at the US Capitol in Washington. (Melina Mara/The Washington Post via AP, Pool) WASHINGTON (JTA) — Setting his administration’s tone in his first speech to Congress, US President Joe Biden said Wednesday that white supremacists posed the “most lethal” terrorist threat to the United States. Biden said the terrorist threat had evolved and referred to his decision to end the US troop presence in Afghanistan after 20 years, when the United States first entered the country to pursue the Al Qaeda terrorists responsible for the September 11, 2001 attacks.