Republican US presidential candidate Ron Paul has announced he is suspending his active campaigning.
Mr Paul released a statement saying he would no longer "no longer spend resources campaigning in primaries."
He had been the only remaining candidate challenging Mitt Romney for the party's nomination.
He insisted his team would "continue to work in the state convention process" and seek to win delegates in order to "carry a strong message" to the Republican National Convention in Tampa, Florida in August.
A Republican candidate needs 1,144 delegates in order to be declared the nominee.
Mr Romney has 949, according to a count by RealClearPolitics, and is expected to wrap up the nomination on May 29 by winning the Texas primary.
Mr Romney's two main challengers - religious conservative Rick Santorum and former House speaker Newt Gingrich - dropped out in April and May respectively, leaving Mr Paul as his lone Republican opponent for the past two weeks.