Former Libyan General Khalifa Haftar was appointed on Monday as the Army Commander of the country's internationally recognized government.
The appointment of Haftar as Commander of the Army was proposed last week by the President of Libya's elected Parliament.
Haftar, a former ally of Muammar Qaddafi who later joined the revolution against the Libyan leader, has merged his forces with army troops in the east to fight Islamist groups including Libya Dawn, which has taken over Tripoli and set up its own rival government.
They operate now as the Libyan National Army, a name the eastern army has adopted.
The confirmation of Haftar may complicate United Nations efforts to broker peace between the country's two rival governments.
Meanwhile, Italy began on Monday annual naval exercises near the coast of Libya, where a breakdown in order has allowed tens of thousands of migrants to try to reach Europe by boat and increased fears of attacks by Islamist militants.
The Navy said in a statement that the exercises, known as Mare Aperto (Open Sea), were suspended last year because of the search-and-rescue mission dubbed Mare Nostrum, which was set up after hundreds of migrants were drowned off the southern island of Lampedusa. Mare Nostrum has now ended and been replaced by a more limited European Union mission known as Triton.
Admiral Pierpaolo Ribuffo, the Officer in command of exercises, said the operation was not directly connected with the crisis in Libya, where Italian energy group Eni has significant offshore oil platforms and other assets.
But he said the presence of naval vessels in the area could help improve security.
“We're training our ships and our men, that’s all. Our activity has nothing to do with other scenarios,” he told Italian news agency ANSA in comments that were subsequently released by the Navy.
“Obviously the presence of ships at sea also means security, deterrence and dissuasion. But that's normal, it's like police patrolling the streets,” he added.
Italy, whose southern islands are only around 300 kilometers from the Libyan coast, has led calls for a global diplomatic push to stabilize Libya. It has also offered help in training a regular Libyan Army but has ruled out any peacekeeping mission for the moment.