ABUJA, Nov 18 (Reuters) - U.S. Secretary of State Antony Blinken on Thursday said the United States will remain very focused on the migration crisis in Belarus after authorities on Thursday cleared the main camps where migrants had huddled at the border with Poland. "It is profoundly unconscionable that Lukashenko and Belarus have sought to weaponize migration," Blinken told reporters during a visit to Nigeria, adding the U.S. has the authority to as necessary add to sanctions.