Northern Ireland Secretary James Brokenshire has said some information regarding the Troubles can never enter the public domain, adding that the current legacy system "is not working for anyone".
Mr Brokenshire said national security remained the top priority for the Government, as he agreed with calls from former Northern Ireland secretary Theresa Villiers to withhold particularly sensitive information.
He also pledged to create new Stormont House bodies to ensure legacy issues were dealt with in a balanced, proportionate and fair way.
Speaking at Northern Ireland questions, Ms Villiers said: "The government and the police have disclosed unprecedented amounts of information about the Troubles, some of it extremely sensitive.
"But will the Secretary of State agree that there is some information that is so sensitive that it can never go out into the public domain, because it would put lives at risk if it did?"
Mr Brokenshire replied: "I do agree with her, and with all of her experience as a previous secretary of state she knows the sensitivity and importance of these issues of national security.
"National security remains the primary responsibility of the UK Government and our actions we will certainly continue to have that at the forefront of our minds."
Conservative MP Sheryll Murray (South East Cornwall) raised the case of constituent Denis Hutchings, a British Army veteran charged with murder for a killing during the Troubles.
Ms Murray said: "Will he ensure that the disgraceful treatment of my constituent, Corporal Major Denis Hutchings, and others will be addressed as part of any further discussions on legacy issues?"
In reply, Mr Brokenshire said: "She will understand that I am unable to comment on individual cases, but I can say to her that the current system in relation to dealing with a range of issues related to legacy is not working for anyone.
"It's not working for service personnel, it's not working for victims too, and why it is important we move forward on the Stormont House bodies and creating that balanced, proportionate and fair system that I think everyone recognises is needed."
Later in the session, DUP defence spokesman Sir Jeffrey Donaldson reiterated his calls for the Government to do more to protect veterans over their actions.
He said: "In the wake of the scrapping of the Iraq inquiries and the judgment today in the case of Alexander Blackman, isn't it time that the Government provided legal protection to the men and women who serve this country on the frontline?"
Northern Ireland minister Kris Hopkins said the Government was committed to protecting veterans and had put huge resources into it.