WASHINGTON—The United States on Tuesday imposed sanctions on two military leaders of the Houthi movement in Yemen, accusing them of procuring weapons from Iran and organizing attacks, in the Biden administration’s first punitive action against the group. The sanctions contrast with the State Department’s decision last month to revoke terrorist designations on the group imposed by President Donald Trump’s administration on its last full day in office, over concern that they would exacerbate Yemen’s humanitarian crisis. But President Joe Biden’s administration has signaled limits to U.S. tolerance of the Iran-backed Houthi movement, warning that Washington will keep up pressure on the group’s leadership. “The United States remains committed to promoting accountability of Houthi leadership for their actions, which have contributed to the extraordinary suffering of the Yemeni people,” Director of the Office of Foreign Assets Control Andrea Gacki said in a Treasury Department statement. Tuesday’s move blacklisted Mansur Al-Sa’adi, the …