UN Secretary-General Ban Ki-moon on Thursday announced his decision to launch an inquiry into the alleged use of chemical weapons in Syria, a probe the Syrian government previously requested.

The secretary-general, speaking to reporters at his office here, said, "I have decided to conduct a United Nations investigation into the possible use of chemical weapons in Syria."

"I intend for this investigation to start as soon as practically possible," Ban said. "The investigation mission is to look into the specific incident brought to my attention by the Syrian government."

The Syrian government on Wednesday asked the U.N. to send an independent mission to investigate a reported chemical weapons attack by rebels in the country's northern province of Aleppo, Syria's U.N. representative Bashar Ja'afari told reporters here.

"I am here to inform you that the Syrian government has requested a few minutes ago the secretary-general of the United Nations to form a specialized, independent, neutral and technical mission to investigate the use by the terrorist groups operating in Syria of chemical weapons yesterday against civilians in the town Khan al-Asal in Aleppo," said Ja'afari, who stressed his government did so in "a sign of good faith, good will, good intentions vis-a-vis the international community and vis-a-vis the international public opinion."

At least 25 people were killed and 130 others wounded Tuesday when armed men fired a rocket stuffed with chemical materials at the Khan al-Asal, said Syrian state media, claiming opposition fighters were responsible. However, the rebels denied the accusations and instead accused the government of committing the misdeed.

Ban said of the probe: "There is much work to do and this will not happen overnight, it is obviously a difficult mission."

"I am, of course, aware that there are other allegations of similar cases involving the reported use of chemical weapons," he said. "In discharging its mandate of an investigation mission, full cooperation from all partners will be essential. I stress that this includes unfettered access."

The United Nations would cooperate with the Organization for the Prohibition of Chemical Weapons (OPCW) and the World Health Organization (WHO), he said.

"Again my announcement should serve as an unequivocal reminder that the use of chemical weapons is a crime against humanity," Ban said. "The international community needs full assurance that chemical weapons stockpiles are verifiably safeguarded."

Meanwhile, the secretary-general repeated what he called "the horrors of the last months and years prove beyond doubt: the military solution in Syria is leading to the dissolution of Syria. "

"I call on the regional and international community to find unity and support the efforts of Joint Special Representative Lakhdar Brahimi to help the Syrian people reach a political solution," he said.

"The two-year long conflict has plunged the country into extreme chaos with terrible consequences for the Syrian people," Ban said. "As the situation worsens, the international community's concern about the safety and security of chemical weapons stockpiles as well as possible use of by all parties has increased. "

"I have repeatedly stated that use of chemical weapons by any side under any circumstances would constitute an outrageous crime, " he said. "Anyone responsible must be held accountable."

"I have emphasized the primary responsibility of the Syrian government to ensure the safety and security of any such weapons or materials," he said.