The leaders of Germany and Britain urged Ukraine and Russia to settle gas dispute as soon as possible on Thursday in Berlin, according to Xinhua.

    German Chancellor Angela Merkel called the gas dispute a "serious development" and thought it will threaten the image of Russia to Europe as a credible gas supplier.

    She urged Russia and Ukraine to restart their negotiation and to resume gas supply as soon as possible. She also said she will discuss the gas issue with Russian Prime Minister Vladimir Putin when he visits Germany on Friday.

    British Prime Minister Gordon Brown said the recent interruption of gas have "reemphasized to the world the need to diversify energy supplies." The two leaders also stressed the need for the European Union to reduce its dependence on natural gas.

    Brown met Merkel Thursday in Berlin to discuss the problems of Middle East crisis, the gas dispute between Russia and Ukraine as well as measures to tackle the economic crisis ahead of April`s G20 meeting in London.