Former Republican U.S. presidential nominee Mitt Romney speaks critically about current Republican presidential candidate Donald Trump and the state of the 2016 Republican presidential campaign during a speech at the Hinckley Institute of Politics at the University of Utah in Salt Lake City, Utah March 3, 2016. REUTERS/Jim Urquhart

WASHINGTON (Reuters) - Republican 2012 presidential nominee Mitt Romney is aiming to block Donald Trump from winning the nomination for president at the party’s convention, CNN reported on Thursday, citing an unnamed source close to Romney.

The goal is to lock him out of the convention, CNN said.