Republican Senator Ted Cruz said Friday he will vote for his former arch-rival Donald Trump despite previously refusing to publicly endorse him after a hard-fought primary battle.
"After many months of careful consideration, of prayer and searching my own conscience, I have decided that on Election Day, I will vote for the Republican nominee, Donald Trump," Cruz wrote on Facebook, pointing to his pledge earlier this year to support the eventual Republican nominee and his desire to defeat Democrat Hillary Clinton.
Cruz drew boos at the Republican National Convention in Cleveland, Ohio, in July when he refused to endorse Trump during a high-profile speech.
Trump said he was "greatly honoured" by Cruz's endorsement.
"We have fought the battle and he was a tough and brilliant opponent," he said in a statement. "I look forward to working with him for many years to come in order to make America great again.”
Cruz said Trump would nominate conservative justices to the US Supreme Court, overturn of President Barack Obama's health care reforms, support the oil and gas industry, crack down on illegal immigration, fight terrorism and end acceptance of Syrian refugees and maintain US control of the internet.
"Our country is in crisis. Hillary Clinton is manifestly unfit to be president, and her policies would harm millions of Americans. And Donald Trump is the only thing standing in her way," Cruz said.
Cruz along with Ohio Governor John Kasich were the last opponents challenging Trump from a crowded Republican presidential primary field and had refused to support him.
The feud between Cruz and Trump was particularly ugly, with the billionaire businessman taking aim at Cruz's wife and accusing his father of involvement in the John F Kennedy assassination.