The United Nations on Tuesday voiced concern amid increasing tensions between rival Libyan factions in the war-torn country.

The U.N.'s mission UNSMIL said it was "following with deep concern the ongoing mobilisation of forces and threats to resort to force" by groups vying for control of the North African country.

Oil-rich Libya has been wracked by conflict since a NATO-backed uprising toppled and killed longtime dictator Moammar Gadhafi in 2011. The country was split by rival administrations, one in the east-backed putschist Gen. Khalifa Haftar and a U.N.-supported administration in the capital of Tripoli in the west. Each side is supported by different militias and foreign powers.

In April 2019, Haftar and his forces, backed by Egypt, Russia and the United Arab Emirates, launched an offensive trying to capture Tripoli. His campaign collapsed after Turkey stepped up its military support for the U.N.-supported government.

An October 2020 cease-fire accord led to an agreement on a transitional government in early February 2021 headed by Prime Minister Abdul Hamid Dbeibah and to the scheduling of elections for last Dec. 24. But the elections weren’t held.

A long-running political crisis deepened in February when an eastern-based parliament picked former interior minister Fathi Bashagha to replace the government of Abdul Hamid Dbeibah.

But Dbeibah, the interim premier appointed last year as part of a United Nations-backed peace process to end more than a decade of violence in the North African country, has refused to hand over power before elections.

In its statement on Tuesday, UNSMIL warned that "the current political stalemate ... cannot be resolved through armed confrontation."

It called for an "immediate de-escalation" said that "the use of force by any party is not acceptable" and would not lead to international recognition.

Bashagha told Agence France-Presse (AFP) last month that Dbeibah's government is "illegitimate", arguing that "its mandate is over and it failed to make elections happen".

On Tuesday, Bashagha's office issued a statement urging "Libyan men of honour" to drop their support for Dbeibah's "obsolete and illegitimate" administration.

That sparked fears of renewed conflict in the capital Tripoli between backers of the two sides.

Bashagha, despite his appointment by the parliament elected in 2014, has been unable to impose his authority in Tripoli, initially ruling out the use of force.

More recently he has hinted that he could resort to force.

Last month, the most deadly clashes between rival groups in Tripoli since 2020 left 16 people dead including a child.