Despite high hopes when a U.N.-brokered agreement for a unity government in Libya was reached in December, the process of actually forming such a government is “facing major challenges,” as the Associated Press delicately puts it.

One of those challenges is that the U.N. envoy has been blocked from flying into Tripoli, which is the national capital, but not the current headquarters of the internationally-recognized legitimate government.

“The envoy, Martin Kobler, said on his Twitter account that he has had to cancel another flight to Tripoli because of this,” the AP reports. “He said he ‘wanted to help pave the way to peace’ and stressed that the United Nations must be given access to the Libyan capital.”

The “rival parliament” squatting in Tripoli is a gang of Islamist warlords, whose enthusiasm for “unity” with the legitimate government, which has been exiled to Tobruk, is debatable. The only real pressure for unity is the extremely alarming growth of ISIS in divided Libya, although fluctuating oil prices might be a wild card in the game.

The Libyans might even be using their internal chaos to squeeze concessions out of OPEC, announcing they will skip an April meeting on a supply freeze, because they insist on being allowed to resume full production when their “security situation improves.”

It is not clear exactly why the western faction is holding Kobler at bay. The “authorities” in Tripoli refused to discuss the matter with the Associated Press, so the best they could do in the way of comment was a Facebook post from a “Tripoli-based media official,” declaring the envoy “will not visit Tripoli before Monday.”

Reuters quotes the office of the theoretically outgoing prime minister in Tripoli, Khalifa Ghwell, claiming they asked Kobler to forward an agenda for his visit, and when they did not receive a reply, they denied him permission to land. They said the same thing happened during several previous attempts by Kobler to visit Tripoli.

Ghwell himself was rather more heated in his criticisms of Kobler and the United Nations, saying in a television interview on Wednesday that U.N. intervention risked creating “chaos” in his country. Chaos is not a commodity Libya needs to import from the United Nations; the home-grown supply is more than adequate.

The new unity prime minister, Fayez Seraj, is supposedly ready to bring his government into Tripoli once security plans with police, military, and armed militia groups have been finalized, an achievement that does not appear to be on the near horizon.