United Nations Secretary General Ban Ki-moon has described the years-long bloodshed in Syria as a “shameful symbol” of global failure and divisions.

On Wednesday, Ban told the UN Security Council (UNSC) that he was “profoundly disappointed” that previous resolutions aimed at preventing further violence in Syria had not been implemented.

“After more than four years of slaughter, the Syrian conflict is a shameful symbol of the international community’s divisions and failure,” Ban said, adding that Syria was the “world’s largest humanitarian crisis.”

He added that “atrocious crimes” were now taking place on an almost hourly basis.

The UN chief further urged the 15-member council to support Special Envoy to Syria Staffan de Mistura’s proposal for talks to end the conflict in Syria.

On July 29, the UN official invited Syrians to participate in what he called “parallel, or simultaneous, thematic discussions through intra-Syrian working groups,” without specifying details regarding the time and place of the talks.

De Mistura also said it was too soon to hold a third peace conference over Syria in the Swiss city of Geneva. The first two peace conferences on Syria were held in Geneva in 2012 and 2014.

Syria has been dealing with a deadly crisis since March 2011. According to reports, close to a quarter of a million Syrians have been killed in the crisis. Nearly half of the country’s population– 12 million people– have been forced to flee their homes.

Editor’s note: This article has been edited from the source material