Veteran Algerian diplomat Lakhdar Brahimi, the UN-Arab League envoy for Syria, has insisted throughout his career that there is no "hopeless situation", but he has not managed to find a magical solution to end Syria's civil war.
And the 79-year-old Brahimi, who took on the job last August after predecessor and former UN chief Kofi Annan threw in the towel, is now ready to give up too.
Annan resigned on August 2, frustrated by the division between supporters in the West and the Arab world of those fighting to oust Bashar al-Assad and traditional backers of the Syrian president, principally Russia and China.
"The decision has been taken, but we don't know when it will be formalised," one UN diplomat said of Brahimi.
Earlier in the week, a senior aide to Brahimi said he "thinks of it [resigning] every day" but would not decide until at least the middle of May.
"He thinks that every step he takes is countered with 10 steps backwards by the Arab states. And now it looks like the Americans will increase their military support [to the rebels], so he feels that he is useless in his role," the aide said.
If Brahimi quits, UN Secretary General Ban Ki-moon is unlikely to appoint a replacement quickly and could even take on the job himself, a UN diplomat said.
Brahimi could keep a role as an adviser to Ban on Syria or the Middle East, according to envoys.
"Ban will not rush to appoint a third person," added another Security Council diplomat. "You have had Annan, you have had Brahimi - are you going to get someone who can do better than them?"
Soon after his appointment, the opposition demanded he apologise for saying he did not know if the time had come to demand that Assad resign. Then, during his third visit to Damascus last Christmas, his talks with Assad broke down when he asked him if he intended to run for the presidency in 2014.
He has faced the wrath of the Syrian press, which strongly criticised his efforts, even calling him a "false mediator".
In October, a bid to establish a ceasefire during a Muslim holiday failed and he has travelled to Moscow, Beijing and Europe's power centres in a bid to end the bloodshed, but without success.