The United States is preparing to increase oil sanctions against Iran over its nuclear programme. President Obama has issued a statement saying there was enough oil on the world market to allow a significant reduction in purchases from Iran. Paul Adams reports from Washington.

就伊朗核武器问题，美国准备升级石油制裁措施。奥巴马总统发表声明：世界市场有足够的石油，因此可大幅减少从伊朗进口石油。Paul Adams从华盛顿报道。

After June, financial institutions that continue to buy oil through Iran's central bank, where almost all such transactions are processed, will face sanctions. White House officials say the president decided to issue his statement after careful consideration of a number of factors, including global economic trends, supply and demand for non-Iranian oil, as well as spare capacity. There are exceptions: the US has already granted waivers to 10 EU countries and Japan because they've taken steps of their own.

六月以后，任何金融机构若继续从伊朗中心银行购买石油将面临制裁，石油交易几乎全部在伊朗中心银行进行。白宫官员说总统是经深思熟虑诸多因素才发表该声明的，包括全球经济趋势，非伊朗石油的供给和需求，及备用能力。其中也有例外，美国授予10个欧洲国家和日本豁免权，因为他们已自行采取了必要的行动。

The international envoy Kofi Annan says he expects the Syrian government to implement an agreed ceasefire immediately. A spokesman for Mr Annan said he wanted the authorities to halt the use of heavy weaponry in towns and withdraw soldiers to barracks because then the opposition would respond. Correspondents say there's no sign yet that the government is in the mood to make gestures to the opposition. There was more heavy bombardment in Homs and other places during the day.