WASHINGTON (AP) — Arizona Sen. John McCain says he’s grateful for the outpouring of support after his brain cancer diagnosis. He’s promising to be back soon.

The junior senator from Arizona says McCain told him about his brain tumor only at the end of a telephone conversation, saying he was “feeling fine, but I might have some chemotherapy in my future.”

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Sen. Jeff Flake says his colleague is “optimistic, obviously. He’s John McCain. That’s what we’d expect.”

The tumor was discovered when doctors removed a blood clot from above McCain’s left eye.

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Speaking Thursday on ABC’s “Good Morning America,” Flake said it is not yet clear when McCain might be able to return to the Senate.

Flake calls him an “elder statesman” and “a steady force, one who stands for the institution and bipartisanship,” adding that he cannot “overstate what an impact he has in the Senate.”

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