Japan on Monday voiced strong concern over the Syrian government\'s alleged use of chemical weapons on civilians, as a UN investigation team will begin on-site investigation on it. \"The use of chemical weapons cannot be accepted under any circumstances. We hope that facts will be revealed by a United Nations team will at the earliest, \" Chief Cabinet Secretary Yoshihide Suga told a press conference. \"Japan will continue making diplomatic efforts in cooperation with the international community to stop all forms of violence,\" the top government spokesman said. Suga\'s remarks came after Syrian President Bashar al-Assads government agreed on Sunday to allow UN inspectors to investigate the site of alleged chemical weapons attack in the suburbs of Damascus last week. Syria\'s opposition forces claimed government troops used poison gas during Wednesday\'s attack, killing hundreds of people. But the government has denied using them.