"Having Donald Trump at the top of the ticket in November would be a sure disaster for Republicans," Cruz’s campaign manager Jeff Roe said in a statement.
"To ensure that we nominate a Republican who can unify the Republican Party and win in November, our campaign will focus its time and resources in Indiana and in turn clear the path for Gov. Kasich to compete in Oregon and New Mexico," Roe said.
Kasich’s senior strategist John Weaver said in a separate statement that, "given the current dynamics of the [Indiana] primary, we will shift our campaign’s resources West and give the Cruz campaign a clear path in Indiana."
On Tuesday, voting will take place in five US states. Indiana will vote on May 3, Oregon on May 17 and New Mexico on June 7.