Libyan armed groups and authorities reached an accord in Tripoli to secure important infrastructure, the country's interior minister announced Friday, following concern from the UN over recent fighting and a brewing crisis surrounding the country's central bank.

The North African country of 6.8 million has struggled to recover from years of conflict after the 2011 NATO-backed uprising that overthrew longtime dictator Moamer Kadhafi.

It remains divided between a UN-recognised government in the capital Tripoli led by Prime Minister Abdulhamid Dbeibah, and a rival administration in the east backed by military strongman Khalifa Haftar.

"In coordination with the Ministry of Defence, we have brought together all the security services of Tripoli and managed to reach an agreement to secure the airports and land borders, as well as the headquarters of government (institutions) in the capital," said Interior Minister Imad Trabelsi, of the UN-recognised government.

The armed groups and security services "expressed their immediate willingness" to put the agreement into force, he added.

"Within 24 hours, we will secure all governmental buildings, including that of the Central Bank of Libya."

The bank's governor since 2012, Seddik al-Kabir, has faced criticism from figures close to Prime Minister Dbeibah over the management of Libya's oil resources and the state budget.

On Tuesday, the acting head of the UN's political mission in the country, Stephanie Koury, told the UN Security Council that in "the past two months, the situation in Libya has deteriorated quite rapidly", citing recent fighting between armed groups on the outskirts of Tripoli and attempts to forcibly expel Kabir.

The UN mission (UNSMIL) on Thursday called on parties to exercise restraint, expressing "grave concerns about reports of mobilization of forces in Tripoli, including the threats to use force to resolve the crisis surrounding the Central Bank of Libya".

The US embassy also raised the tensions around the bank on Thursday night, saying any attempt to resolve matters by force would impact the institution's integrity and its position in the global financial system.

Around two weeks ago, several dozen people, some of them armed, gathered in front of the bank's headquarters in a bid to force Kabir to resign.

And last Sunday, the director of the bank's IT department was briefly kidnapped by an unidentified group, prompting the institution to suspend operations until he was released.