The Pentagon's top lawyer on Thursday said the Obama administration remains committed to closing the Guantanamo Bay prison by early next year but stopped short of assuring it will happen.

Pentagon general counsel Jeh Johnson's comments came as Congress weighs how to revamp a military court system — a key part of President Barack Obama's pledge to close Guantanamo by Jan. 22.

A number of legal questions remain on how to prosecute and detain the 226 suspected al-Qaida, Taliban and foreign fighters currently held at the U.S. military prison in Cuba. That has cast doubt on whether the Obama administration can resolve the questions in just over four months, and prompted top Republicans in Congress to demand that the prison stay open for now.