The European Commission Thursday formally requested Belgium, Cyprus, the Czech Republic, Portugal and Romania to take action to ensure full compliance with their obligations under EU legislation on oil stocks. The legislation requires that EU member states maintain minimum stocks of crude oil and/or petroleum products to ensure security of the oil supply in case of possible disruptions. Given the importance of oil in the EU\'s energy mix, the EU\'s strong external dependence for supply of crude oil and petroleum products and the geopolitical uncertainty in many producer regions, it is vital to guarantee consumers\' access to petroleum products at all times, said the Commission in a statement. If the five EU member states do not comply with their legal obligation within two months, the Commission said it may decide to refer them to the European Court of Justice. The legislation had to be transposed into their national laws by the EU member states by 31 December 2012. Administrative procedures were opened in January 2013 against 17 EU Member States that had failed to implement the EU law, noted the statement.