BENGHAZI, Libya (Reuters) - Veteran military commander Khalifa Haftar, the most powerful figure in eastern Libya, returned to Benghazi on Thursday after a two-week absence during which he received medical treatment in Paris.

FILE PHOTO: Libya's eastern-based commander Khalifa Haftar salutes as he participates in General Security conference, in Benghazi, Libya, October 14, 2017. REUTERS/Esam Omran Al-Fetori

Haftar, 75, smiled and joked as he greeted a delegation of senior officials after stepping off a late afternoon flight from Cairo.

“I want to reassure you that I am in good health,” he told senior army commanders and local elders in a televised address from the airport shortly afterwards.

“I should be addressing you standing up but I am obliged to do so sitting down,” Haftar quipped, seated in front of a bank of microphones on an ornate table.

Authorities in eastern Libya did not issue any pictures or detailed information about his health during his stay in Paris, fuelling speculation over his condition and the possible impact on the balance of power in Libya.

“I won’t respond to those promoting rumors about my health, and you are not responsible for them. But there are those who will answer for them in the appropriate way,” Haftar said.

Libya fragmented after a 2011 uprising that ended more than four decades of dictatorship under Muammar Gaddafi, and has been divided since 2014 between rival governments and military alliances based in the east and the west.

The United Nations has been leading an effort to stabilize and reunify the oil-rich nation of six million and has said it hopes to hold national elections by the end of the year.

Haftar, a former commander in Gaddafi’s army who turned against him and returned to Libya to join the 2011 uprising, has gradually extended his grip on Libya’s east and parts of the south, taking full control of Benghazi last year after a three-year military campaign.

With support from President Abdel Fattah al-Sisi’s Egypt and the United Arab Emirates, he has promised to drive out Islamist militants and “liberate” Tripoli, bringing the capital’s militias to heel.

He has opposed a U.N.-backed transitional government that has been trying to establish itself from Tripoli for the past two years.

Since 2016 Haftar has also controlled all the oil ports and main fields in the east, where most of Libya’s oil resources are concentrated.

But he has remained a divisive figure, viewed by opponents as an old-fashioned military strongman who seeks to reimpose authoritarian rule across Libya and labels all his rivals as terrorists.

He has also struggled to contain local divisions and power struggles in Libya’s east. Armed rivals of his Libyan National Army (LNA) have resisted encirclement to retain control of the eastern city of Derna.