The European Union’s exasperation with Greece burst into the open on Sunday when its chief executive rebuked leftist Prime Minister Alexis Tsipras and warned that time was running out to conclude a debt deal to avert a damaging Greek default. In unusually sharp terms, European Commission President Jean-Claude Juncker accused Tsipras of distorting proposals by international creditors for a cash-for-reform agreement and of dragging his feet in offering an alternative.