Ukraine has asked the European Union for an additional loan of $ 2.5 billion as it struggles to cope with the implications of its standoff with Russia.

EU Commission spokesman Simon O'Connor said Tuesday that the request will be "evaluated in consultation with the IMF and Ukrainian authorities." However, he insisted that the EU's executive office "remains very committed to supporting Ukraine in line with earlier commitments."

His comments came as the energy chiefs of the EU, Ukraine and Russia meet Tuesday in Brussels to try to overcome the financial differences standing in the way of assuring Russian gas supplies to Kiev this winter.

Russian President Vladimir Putin and his Ukraine counterpart Petro Poroshenko have reached agreement on the broad thrust of a deal but financing issues remain.