The US Congress' failure to wrap up its annual defence policy bill before going on summer vacation is giving the Obama administration more time to lobby lawmakers on two key issues - shuttering the military prison at Guantanamo Bay and how to respond to the fatal shootings of military service members in Chattanooga. Both issues have emerged as key sticking points as Senate and House negotiators sought to wrap up work on the fiscal 2016 defence authorisation bill. Now, the Obama administration has a chance to use the delay as an opening to put its imprint on the legislation. Last Thursday, the Pentagon instructed the secretaries of the military departments, combatant commands and the National Guard to develop "action plans" to better "arm qualified DoD personnel for security, law enforcement and counterintelligence duties," as well other DoD employees "not regularly engaged in law enforcement" at smaller, off-base military facilities, in light of the deadly shootings at a recruiting station and a naval reserve centre in Chattanooga last month. Negotiators on the final bill had been considering a House proposal that would allow troops at military facilities to arm themselves before the July 16 shooting took place. But in light of that event, lawmakers decided to reexamine "whether that is adequate," said House Armed Services Committee Chairman Mac Thornberry. "There is widespread agreement that military folks ought to be able to defend themselves; now it's getting the details right in the various situations, environment in which they find themselves." Some lawmakers said the issue should wait until the Defence Department provides its input. Defence Secretary Ash Carter indicated proposed changes to the Pentagon's policy should be submitted by August 21. But there is no date yet for when the Obama administration will produce a plan of action that would potentially affect the defence authorisation bill's final stance on Guantanamo. Earlier this month, the White House indicated it was close to delivering Congress a specific plan for the closure of the detainee facility at Guantanamo Bay, Cuba. The Senate version of the defence authorisation bill includes a provision that would ensure Congress then takes a look at that plan and decides whether or not to endorse the proposal. But the House version includes no such nod - and without it, the ban on bringing any prisoners currently housed at Guantanamo to detention facilities in the United States would be reaffirmed. This would make it near to impossible to effectively close the facility, even if the administration keeps transferring detainees overseas. Senate Armed Services Committee Chairman Senator John McCain, has long complained that the lack of a formalised White House plan has hamstrung efforts to close the Guantanamo prison - a goal that in theory, he supports. With such a plan in hand, the push to compel a vote on it would likely gain more urgency. But even if the administration and Congress find common ground on these issues, the ultimate fate of the defence policy bill is far from certain. Differences between the House and Senate over raising troops' pay, slowing the growth of their housing allowances and raising prescription drug co-pays for those insured through the Defence Department were all complicating lawmakers' negotiations last month. And President Barack Obama's veto threat is hanging over all of it.