China pledged to take a greater role in global issues on Thursday as it vowed to work with the European Union on nuclear non-proliferation, energy security and climate change.In wide-ranging talks between Chinese Premier Wen Jiabao and European Commission President Jose Manuel Barroso, the two sides also agreed to fight protectionism and tear down trade barriers.During the talks, both leaders vowed to reduce trade barriers and ensure level playing fields for enterprises both in Europe and China, Wen said.On the Iranian nuclear issue – a key concern of the EU and United States – Wen did not say whether Beijing would support new sanctions on Tehran. He only said that China was committed to the global nuclear non-proliferation regime and upholding peace in the Middle East.