(CNN) Marco Rubio says he plans to attend the Republican convention, will release his delegates to vote for Donald Trump and would be willing to speak on Trump's behalf.

"I want to be helpful. I don't want to be harmful, because I don't want Hillary Clinton to be president," Rubio told CNN's Jake Tapper in an interview.

"Look, my policy differences with Donald Trump -- I spent 11 months talking about them. So I think they're well understood," Rubio said. "That said ... I don't want Hillary Clinton to be president. If there's something I can do to help that from happening, and it's helpful to the cause, I'd most certainly be honored to be considered for that."

He also said his political aspirations aren't over, calling it a "safe assumption" that he'll run for office -- the presidency or something else -- again.

"I can tell you I enjoy public service. If there's an opportunity to serve again in a way that I feel passionate about, I'll most certainly think I would explore it," Rubio said. "But I don't know where I'm going to be in two years. I don't know what my life will look like then."

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