President Obama declined to say Friday whether he will do an end-run around Congress in his effort to close the military prison at Guantanamo Bay, Cuba, but left open the possibility.

His administration must submit a plan and cost estimates for doing so to Capitol Hill early next year. Obama said he would wait until Congress has reviewed that plan and weighed in before deciding whether he will pursue executive action.

"I'm not going to automatically assume that Congress says 'no,'" Obama said about the plan that is still being drafted. "I think it's fair to say that there's gonna be significant resistance from some quarters" to his ultimate closure plan, he added.

But administration officials have left open the possibility that he would issue another executive order, or reinforce the one he signed almost immediately after taking office, to close the terrorist detention facility. That possibility has led to significant criticism from Republicans who have said Obama routinely violates the Constitution by ignoring the will of Congress.

The GOP has also warned that closing the facility would push terrorist suspects detained in Cuba either to the U.S., or to other countries that may not hold them as long.

""[W]e will wait until Congress has said definitively 'no' to a well thought out plan with numbers attached to it, before we say anything definitive about my executive authority here," Obama said.

"I think it's far preferable if I can get stuff done with Congress," he added.