Russian President Dmitry Medvedev promised closer energy cooperation with Germany at the start of his first official trip to western Europe on Thursday. Medvedev, who was sworn in last month, said he hoped Russia's relations with its leading trading partner would deepen further under his leadership. “We had open and honest discussions, typical in our relations, which can become a model for Russian-EU relations,” Medvedev said after talks with German Chancellor Angela Merkel. Both Merkel and Medvedev defended plans to build a Baltic Sea pipeline to deliver Siberian gas to Europe, a project that has sparked concerns about environmental issues and energy security in some east European and Scandinavian countries. Warsaw fears the Nord Stream, which bypasses its territory, would enable Russia to cut off gas supplies to Poland while continuing to deliver to western Europe. Merkel said she hoped other countries' concerns could be eased. “Hopefully, the project will be implemented within the deadlines we talked about,” Medvedev said. Security of energy supply is a major issue for Europe, which gets 25 percent of its energy from Russia, while Moscow has argued with transit states such as Ukraine and Belarus. Merkel said the issue of energy security would feature high in talks between the EU and Russia on a new partnership deal, due to be launched at a summit this month. Asked about possible investments by Russian firms in Germany's national energy network, she said Berlin would not hinder them because they were business decisions. “I will promote this project, which is in the interest of many countries,” Merkel said after talks with Russian President Dmitry Medvedev in Berlin on his first European visit after taking office in May. “I will strive to overcome all objections,” she added. The deal to build the pipeline was inked by Medvedev and Merkel's predecessors Vladimir Putin and Gerhard Schroeder shortly before the former German chancellor left office in late 2005. “Germany has always regarded Russia as a reliable partner and this will continue to be the case,” Merkel said. The Nord Stream pipeline is intended from 2011 to carry natural gas 1,200 kilometers (740 miles) from Vyborg in Russia to Greifswald in Germany, to supply energy-hungry western Europe. Russian gas and oil - 20 billion euros ($31 billion) worth of which was bought by Germany alone in 2007 - currently arrives through pipelines going via eastern European countries like Ukraine and Poland. The project has outraged these former communist states because it means they will lose out on lucrative transit fees when the pipeline becomes one of the main arteries carrying gas to western Europe. Baltic states on or near the planned route have also expressed concerns about potential environmental hazards arising from the pipeline. The Nord Stream consortium is controlled by Russian energy giant Gazprom and also includes Germany's EON and BASF. Russia has regularly been accused of using Gazprom's control of a hefty slice of Europe's gas market for political ends. Russia last summer unveiled a similar plan intended to keep a lock on southern Europe's gas market, a pipeline that would run under the Black Sea to Bulgaria and beyond to other European states.