The European Union Thursday declined to comment on the huge multi-billion dollar 30-year gas agreement signed between Russia and China yesterday during the visit of Russian President Vladimir Putin to China. "We cannot comment on a deal between third countries," said EU spokeswoman for energy Sabine Berger in reply to a question by the Kuwait News Agency (KUNA) during a news conference here today. She added that "Europe has been a very reliable and attractive market for Russian gas for many years. And therefore we expect our suppliers to be equally responsible and honour the contracts that we have concluded." Analysts think that Russia is concerned about possible EU sanctions on its energy sector due to the Ukraine crisis and hence is seeking other markets in the world. About 15 percent of natural gas consumed in the EU comes from Russia via Ukraine