BRUSSELS - European Union leaders will on Thursday reaffirm their full commitment to the 2015 nuclear deal between Iran and world powers, regardless of whether an increasingly critical United States pulls out.But the bloc, reluctant to isolate itself completely from Washington, is also looking at whether it should as a next move step up criticism of Iran's ballistic missile program and its role in what the West sees as fomenting instability in the Middle East, a senior EU official said.President Donald Trump last week adopted a harsh new approach to Iran by refusing to certify its compliance with the nuclear deal, struck with the United States and five other powers including Britain, France and Germany after more than a decade of diplomacy.EU leaders will "reaffirms (their) full commitment to the Iran nuclear deal," after talks in Brussels on Thursday, according to a draft statement seen by Reuters.The EU has been stepping up efforts to save the deal, saying it was crucial to regional and global security, and has appealed to the US Congress not to let it fall.