After years of sabre-rattling, eastern Libyan commander Khalifa Haftar ordered his troops on Thursday to march on the capital Tripoli, escalating a conflict with the internationally recognised government.

Seeking to encircle the capital his forces approached from south and west, seizing one town south of the city before stopping for the night some 60 km (37 miles) south of Tripoli, eastern officials said.

The offensive marked a dramatic escalation of a power struggle that has dragged on in Libya since the overthrow of Muammar Gaddafi in 2011.

The capital is the ultimate prize for Haftar’s eastern parallel government. In 2014 he assembled former Gaddafi soldiers and in a three-year battle seized the main eastern city of Benghazi, then this year took the south with its oilfields.

The offensive surprised the United Nations, whose Secretary-General Antonio Guterres flew on Wednesday to Tripoli to help organise a reconciliation national conference.

Asked about the offensive, Guterres said Libya needed a political, not a military, solution. His Libya envoy Ghassan Salame sat next to him stone-faced with folded arms.

Guterres stayed in the fortified U.N. compound on Tripoli’s outskirts for the night and plans to meet Haftar on Friday, a U.N. spokesman said.

But there was no sign that the east was willing to stop a move that was announced by Haftar in a speech full of talk about victory.

“To our army which is stationed at the outskirts of Tripoli. Today we complete our march,” he said in an audio tape.

Haftar, called “Mushir” by supporters, which means “field marshal” in Arabic, has built his name by fighting Islamists. But many of his opponents see him as a new Muammar.

Since Gaddafi’s downfall, the country has been divided between the U.N.-backed government in Tripoli and the parallel administration allied to Haftar.

Armed groups from the coastal city of Misrata, who oppose Haftar, moved to Tripoli to defend it, residents said.

The governments of France, Italy, the United Arab Emirates, Britain and the United States said in a joint statement that they were deeply concerned about the fighting.

The offensive stared with the capture of Gharyan, a city some 80 km south of Tripoli after brief skirmishes with forces allied to Tripoli-based Prime Minister Fayez al-Serraj. (Reuters)

•Khalifa Haftar, the military commander who dominates eastern Libya, arrives to attend an international conference on Libya at the Elysee Palace in Paris, France, May 29, 2018. REUTERS/Philippe Wojazer