Sen. Ted Cruz, R-Texas, said Tuesday that he's willing to resume his presidential campaign if one of the remaining states were somehow to break in his direction, although he indicated it wasn't likely.

"I'm not holding my breath," he said on The Blaze radio when asked what he would do if he were to win Nebraska tonight. "But listen, let's be very clear, if there is a path to victory, we launched this campaign intending to win ... if that changes, we will certainly respond accordingly."

Cruz didn't act as if he thought that were a serious possibility, but he also refused to endorse presumptive Republican presidential nominee Donald Trump. Cruz also implied that Trump shouldn't rest too easily between now and the Republican National Convention in July, although he didn't speak as if he'd be the next rival to Trump this year.

Cruz demurred when asked if he could endorse Trump.

"This is a choice that every voter is going to have to make and I would note it's not a choice that we as the voters have to make today," he said. "The Republican convention isn't for another two-and-a-half months; the election isn't for another six months. You and I both want to support a conservative."

Trump will face a "ferocious" negative media campaign, one that Cruz seems to think could change how Republicans view Trump. "The voters in the primary seem to have made a choice and we'll see what happens as the months go forward, but I think we need to watch and see what the candidates do," he said.

Cruz also didn't denounce the idea of a third-party campaign by another conservative presidential hopeful, although he said he didn't think that would materialize.

"I don't think that's very likely but its always talked about, I don't know that it's something that's likely to happen," he said. "What I do think is imperative is that we actually get the job done."