UNITED NATIONS — International efforts to end the war in Syria faltered further on Tuesday as the United Nations mediator quit, citing frustrations over the moribund political negotiations, and France’s top diplomat said there was evidence the Syrian government used chemical weapons more than a dozen times after it signed the treaty banning them.  Taken together, the two events pointed to the failings of the West’s signature efforts on Syria, finding a diplomatic way out of a civil war in its fourth year — and a pact that was proudly touted as stopping the Syrian government from using chemical weapons.  The United Nations secretary-general, Ban Ki-moon, announced that he had accepted the resignation of his special envoy, Lakhdar Brahimi, who told reporters, “It’s very sad that I leave this position and leave Syria behind in such a bad state.”  His departure — without a hint of who might succeed him — signaled the bleak prospects for peace in a conflict that has claimed more than 150,000 lives and shows no signs of abating as President Bashar al-Assad says he intends to serve another seven-year term after staging elections in June. Mr. Brahimi’s announcement came just two days before Secretary of State John Kerry and his counterparts from European and Arab nations are to gather in London to discuss the crisis in Syria, with no new or obvious path forward.  Asked for his message to the Syrian people, Mr. Brahimi said later in the day: “Apologies once more.”  There were also signs of disarray within the Western coalition on Tuesday as France’s foreign minister, Laurent Fabius, expressed regret that the Obama administration had decided against using force after a chemical weapons attack in the Damascus area last Aug. 21 that Western nations, led by the United States, blamed on forces loyal to President Assad.  Though an American military strike was called off when Syria agreed to give up its chemical weapons, Mr. Fabius said there were “indications” that Syria had since waged 14 chemical attacks.  “Right now, we are examining the samples that were taken,” he told reporters.  France, Mr. Fabius indicated, had been prepared to use force last year as part of an American-led coalition, but had not wanted to act alone. Had such a military strike been carried out, Mr. Fabius said, “we feel that it would have changed many things.”  While France had previously indicated its chagrin over the Obama administration’s military pullback on Syria, it was unusual for France’s top diplomat to speak so frankly about it — in Washington no less, after a meeting with his American counterpart, Mr. Kerry.  Mr. Fabius’s assertions of chemical weapons use, most of them involving chlorine bombs, came as other signs pointed to Syrian government culpability. Human Rights Watch, in a report on Tuesday, said it had evidence that Mr. Assad’s forces had dropped chlorine-filled bombs from helicopters on three towns in northern Syria in April. The chemical weapons treaty that Syria signed last year prohibits using chlorine as a weapon, even though chlorine itself is not banned.  The State Department had no comment on Mr. Fabius’s assertions of chemical attacks, saying the matter was being investigated by the Organization for the Prohibition of Chemical Weapons. The Russian ambassador to the United Nations, Vitaly I. Churkin, likewise urged patience until the investigation was finished.  Western officials have said in recent weeks that they were aware of reports that the use of chlorine might have occurred more than a dozen times.  Foreign Minister Laurent Fabius said there were strong indications that the Syrian government had carried out attacks using chemical agents in recent weeks.  Credit By Reuters on Publish Date May 13, 2014  Credit Karen Bleier/Agence France-Presse — Getty Images  The State Department on Tuesday defended President Obama’s decision to refrain from using force, saying that it led to an agreement that has eliminated 92 percent of Syria’s precursor chemicals, which are used to make poison gas, and noting that it was pushing Syria to give up the rest.  Ahmad Jarba, the head of the moderate Syrian opposition, who met with President Obama on Tuesday, has been urging the Americans to arm select rebel groups with surface-to-air missiles. The White House has long been reluctant to take such a step, fearing that they would fall into the wrong hands.  Mr. Brahimi, 80, a veteran Algerian statesman who helped negotiate an end to Lebanon’s civil war nearly a quarter-century ago, spoke to a closed-door session of the Security Council after his resignation announcement. He pointedly told its members that they needed to take steps to stop the flow of arms to both sides in the war and to address the dire humanitarian crisis.  Western countries have faced off against Russia repeatedly in the Council; the impasse has meant that the Council has been unable even to ensure that United Nations agencies can ferry food and medicine into the country.  Mr. Brahimi led government and opposition representatives in two rounds of talks in Switzerland. The last ended without agreement even on an agenda for talks. Elections would defy one of the central premises for the negotiations: to discuss how to form an interim transitional government.  Mr. Brahimi also told the Security Council on Tuesday that Iran, the Assad government’s staunch regional ally, had offered to help postpone elections in Syria. “It is too late in the day for that,” he told the Council, according to his prepared remarks, adding that Tehran’s other ideas could still be considered. They included a cease-fire, a new national unity government, and a review of the constitution to reduce the powers of the president.  Mr. Ban was unusually forthright in his remarks on Tuesday, singling out what he described as the Syrian government’s intransigence in political negotiations. He also chided members of the Security Council for their inability to coax allies on the ground in the conflict, suggesting that it was a major reason for Mr. Brahimi’s departure.  “That his efforts have not received support from the United Nations body that is charged with upholding peace and security and from countries with influence over the Syrian situation is a failure of all of us,” Mr. Ban said.  Abu al-Ghaith, 33, a fighter with the Free Syrian Army, dismissed events at the United Nations, saying that diplomats had done nothing but talk. “Nothing will good will happen even if they change the man who is responsible for the Syrian file at the U.N.,” he said. Rami al-Sayyed, a resident Yarmouk, said, “Frankly we don’t care who will come after Brahimi. The international community has let us down.”  Meanwhile, Russia announced that it had circulated a draft Security Council resolution that would seek to replicate local cease-fires, as the warring parties had negotiated in the devastated city of Homs, so humanitarian aid can be delivered. Russia’s Western rivals are discussing two separate measures. One would enforce a humanitarian aid resolution that the Council has already passed and that the warring parties, particularly the government, has repeatedly flouted. The second would refer the war in Syria to the International Criminal Court.  Mr. Churkin said he would reject such a referral.  Somini Sengupta reported from the United Nations, and Michael R. Gordon from Washington. Alan Cowell contributed reporting from London, and Rick Gladstone from New York.  A version of this article appears in print on May 14, 2014, on page A10 of the New York edition with the headline: U.N. Mediator on Syria Quits; Envoy Says Chemicals Were Used. Order Reprints|Today's Paper|Subscribe
Even as the mediator, Lakhdar Brahimi, expressed frustration over stalled talks, France’s foreign minister accused the Syrian government of carrying out chemical attacks after signing a treaty.