"This is a step by Libya to be clean of all nuclear weapons and weapons of mass destruction," Scientific Research Minister Maatoug Muhammad Maatoug said on Wednesday after signing the accord with Muhammad ElBaradei, head of the International Atomic Energy Agency (IAEA).
ElBaradei told reporters: "Libya's decision could be, and should be, a first step towards an Africa and Middle East free from weapons of mass destruction and at peace."
Earlier, the IAEA's governing board passed a resolution praising Libya for dismantling its secret nuclear weapons programme and commending Tripoli to the Security Council.
Diplomats said the resolution noted Libya's past nuclear activities had put it in breach of the nuclear Non-Proliferation Treaty (NPT) but applauded its current disarmament moves.
The moves marked significant fresh steps by Libya - long branded as a rogue state for sponsoring attacks like the 1988 Lockerbie airline bombing - to reintegrate itself into the international community.
Tripoli made the surprise announcement last December it was abandoning all WMD programmes and would cooperate with the IAEA, the United States and Britain to dismantle them.
On Saturday, Libya dispatched a shipload to the United States containing all the equipment believed to remain from its nuclear weapons programme, along with longer-range missiles and launchers.
"This is a step by Libya to be clean of all nuclear weapons and weapons of mass destruction"
Maatoug Muhammad Maatoug,
scientific research minister, Libya
On Monday, the IAEA supervised an airlift from Tripoli to Russia of 80% enriched uranium from a reactor near the capital. The agency said the metal was almost pure enough to be used in a nuclear weapon.
Asked if there would be further shipments of uranium or nuclear-related equipment, Maatoug told reporters: "There's nothing still to be removed."
Under the additional protocol, IAEA inspectors can obtain short-notice access to any declared or undeclared sites where nuclear material may be present, in order to check for evidence of banned weapons activity.
In recognition of Libya's efforts, the Bush administration announced last month it would allow US oil firms to begin negotiating to resume operations, long banned under US sanctions.
It also eased restrictions on US travel to Libya and decided to let the North African country establish a diplomatic presence in Washington following a US decision to base several of its own diplomats in Tripoli.