The Pentagon is planning to send its detailed plan for closing the U.S. military prison at Guantanamo Bay to Congress. Pentagon spokesman Capt. Jeff Davis said the administration is aiming to meet the Tuesday deadline to present a plan to shutter the facility, where 91 prisoners still remain. President Obama has vowed to close the prison since 2009 and renewed his pledge to do so before he leaves office next January. The plan will include outlining costs for upgrading U.S. facilities where inmates could be transferred, Reuters reports, citing sources familiar with the matter. However, Republicans and some Democrats remain opposed to proposals to move Guantanamo prisoners to U.S. soil. Congress has banned any transfers of inmates to maximum-security prisons in the U.S. since 2011.