The international community lacks the moral motivation to end the Libyan civil war and largely views the country as a prize to be captured, the UN’s special envoy for Libya has said.

Ghassan Salamé’s complaint came as one of the belligerents in the civil war, Field Marshal Khalifa Haftar, ruled out an immediate ceasefire in talks with the French president, Emmanuel Macron, in Paris.

Haftar, who launched a military offensive to capture the capital, Tripoli, on 4 April, said the conditions for a ceasefire did not presently exist but he accepted that a political dialogue was necessary.

France has been accused of giving covert support to Haftar, the authoritarian leader of the self-styled Libyan National Army, and Macron is probably the European politician with the greatest influence over Haftar. The LNA, largely based in eastern Libya, claims the UN-recognised Government of National Accord, led by the prime minister, Fayez al-Serraj, is dominated by criminals and Islamist militia.

In a statement, the French government urged Haftar to “ensure the protection of civilian populations, as well as to work towards the establishment of a ceasefire and the resumption of political negotiations”.

Macron said his priorities were the fight against terrorist groups, dismantling trafficking networks, particularly related to illegal migration, and stabilising Libya in the long term.

Salamé, an experienced Lebanese diplomat, said the conflict was likely to grow more vicious without any need for external funding, and it was likely to mutate and create a corridor for migrants and terrorists that would threaten Libya’s neighbours.

Speaking at the International Peace Institute in New York, he said: “The truth is that Libya can pay for its own suicide. I always considered my compatriots in Lebanon as stupid enough to commit suicide with somebody else’s money. The Libyans are even worse. They are committing suicide with their own money. You do not need external fuel for this war. This country is producing 1.2m barrel per day of oil. This is big money. The country is very wealthy. The conflict does not depend on financial transfers from outside.”

He pointed out that the two warring sides had so far committed only 30% of their forces, with little fighting in heavily populated areas.

He said: “I am not sure the some leading countries in the security council are fully aware of the risks they are taking by allowing the conflict to fester. This particular conflict can transform, it could mutate in a few months so we truly regret that we did not stop it on time.

“The way people see Libya is as a prize for the shrewdest, the strongest, the most patient and very much less as a country of 6 million people that deserves a decent life after four decades of dictatorship and a decade of chaos. There is not enough of a moral motivation to put an end to this war and therefore there is less of a political predisposition to make the extra mile to find a solution.”

He said “blatant recent televised breaches” of a UN arms embargo had put the credibility of the whole UN at stake. “The UN should realise it is not been taken seriously when the violations are so blatant and exhibitionist.”

Despite his criticisms of Haftar’s attempt to seize the capital, Salamé said Haftar was “not a phenomenon that you can ignore”.

“If you are looking for a peace formula, you cannot ignore somebody that is not in control but is the largest influence over 75% of territory and 70-75% of the oilfields,” he said. “You cannot say ‘he does not exist, I do not want to deal with him’.”