The United Nations says the Syrian government has a duty to allow humanitarian aid to all areas under siege. Syria has approved aid deliveries to seven besieged areas, but the UN special envoy Staffan de Mistura said the UN had to have access to all Syrians in need. Our diplomatic correspondent James Robins reports. "This is an increasingly tense week after key world powers including Russia agreed to work towards a partial ceasefire in Syria. But neither the Syrian government nor opposition forces were involved and the UN envoy Staffande Mistura is meeting Syria's foreign minister in Damascus trying to persuade his government to stop fighting and allow unhindered humanitarian access to all besieged areas.______________________________________ 联合国表示,叙利亚政府有义务让其境内所有被战火围困的地区人民接受人道主义援助.叙利亚已同意联合国对其境内七个被战火围困的地区运送援助物资,但联合国特使斯坦芬?德?米斯图拉表示,叙利亚必须对联合国敞开其境内所有急需援助的地区.我们的外交记者詹姆斯?罗宾斯报道."随着几个主要的世界强国包括俄罗斯同意执行局部地区停火协议后,这周局势也不断紧张起来.但叙利亚政府和其反对势力都没有卷入其中.联合国特使米斯图拉正在大马士革会见叙利亚外交部长试图说服其政府停战并允许联合国对其境内所有被战火围困的地区提供人道主义援助.________________________________________________________