European Union member states are only slowly increasing overseas aid and need to nearly double their efforts if they are to hit their 2015 target, a report said on Monday. A report on 2013 Official Development Assistance (ODA) prepared for the 28 member nations showed they provided 56.5 billion euros in aid that year, up from 55.3 billion euros in 2012. Collectively for 2013, they spent 0.43 percent of gross national income (GNI), a measure of total annual economic output, the report said. At the current rate of increase, ODA will likely amount to only 0.45 percent of GNI by 2015, needing another 41.3 billion euros to hit the target of 0.7 percent. The European Council, which groups the EU political leadership, said it "remains seriously concerned about ODA levels" and reaffirmed the commitment to aid targets. Member states falling short of their individual targets "are invited to take realistic, verifiable actions" so as to make up lost ground, a statement said. "The EU and its member states call on all other international development partners ... to raise their level of ambition, thus contributing their fair share to global development efforts," it added. The 0.7 percent GNI target was agreed in 2005 as part of a wider EU commitment to the UN Millennium Development Goals. Newer member states have a 0.33 percent target. The Council statement showed that only four EU member states had met or exceeded the 0.7 percent target -- Sweden, Luxembourg, Denmark and Britain -- while none of the others had met their 0.33 percent commitment in 2013.