希腊总理齐普拉斯在意大利罗马参加欧盟特别峰会。 新华社记者金宇摄

Greek Prime Minister Alexis Tsipras signs the "Declaration of Rome" during a ceremony at Capitoline Hill in Rome, Italy, on March 25, 2017. European Union (EU) leaders on Saturday marked the 60th anniversary of the Treaty of Rome founding the integration process, with a major ceremony in the Italian capital. (Xinhua/Jin Yu)