BRUSSELS — With market pressure on their single currency easing for now, will EU leaders meeting here Thursday and Friday return to bickering and delaying promised reforms that could solve the euro crisis?

A pledge in September by the European Central Bank to buy unlimited quantities of bonds has steadied borrowing costs in some of the most vulnerable eurozone countries like Spain. And with negotiations still up in the air over providing more assistance to Greece, the focus of the EU meeting here is expected to be on making Europe’s economic union more cohesive.