Sen. Tom Cotton of Arkansas, the freshman senator who made a name for himself with his opposition to the Iran deal, is crisscrossing the country to campaign for fellow Republicans and although he did not rule out serving as Donald Trump's running mate, he says he's focused on keeping the Senate in Republican hands.

U.S. News spoke exclusively with the freshman GOP senator ahead of the South Carolina Republican Party's Silver Elephant dinner -- an annual state party gala -- in Columbia, where he was the featured speaker last Friday.

Cotton fielded inquiries about whether he would be Donald Trump's running mate, his biggest accomplishment in the U.S. Senate so far and the odds he'll one day be a presidential candidate himself.

Excerpts:

This will obviously set off speculation that you want to run for president one day, right? You realize that?

Well, what I'm committed to is trying to build our party and make sure that we hold our Senate majority to the extent that I can, and also try to help out friends of mine in the House and the Senate. When they invite me to go, I try to go. I've been in Missouri, I've been in Minnesota, I've been in New Hampshire. I was in Arizona yesterday. I've been in Pennsylvania for Pat Toomey. I expect to be in Colorado after their primary, working hard for Joe Heck [in Nevada] as well, trying to make sure he wins that race. So, I expect to be on the road quite a bit.

Would you accept an offer to be Trump's running mate?

(Laughs) I haven't seen it floated out there. Like I said I've been focusing my political work on making sure that we hold the Senate and focus the rest of the time on my son.

So that's not ruling it out?

I wouldn't rule it in either.

So you'll be voting for Donald Trump in November?

I've said all along, I'll support the nominee, because we can't afford another term of the Obama-Clinton foreign policy or for that matter, economic policy at home. And now Donald Trump's the presumptive nominee. So we obviously need to do some work to unify around our common and shared principles and Donald's got the responsibility and opportunity to do that in the coming weeks.

Who did you vote for in the Arkansas primary?

(Laughs) Secret ballot.

What do you make of the divide in your party right now? Isn't this a bit of an unprecedented situation, where you have sitting senators, congressmen, saying they won't support the nominee?

I think over time, the healing power of time, and also the prospect of a third Obama-Clinton term will bring most Republicans together.

And those that are out there saying there should be a third-party movement for conservatives. You would say what to them?

I think it's important that the Republican Party remain the home of conservatives and that the best way to advance conservative principles is to elect Republicans, up and down the ballot.

What would you say your biggest accomplishment is as a U.S. senator so far?

I think that the public debate that we had on the Iran deal was very important. That's probably one of the most consequential things most of us will ever vote on, a nuclear arms control agreement with a mortal enemy. And the White House, despite, all their efforts – failed miserably. Two-thirds of the American people realize just how bad the nuclear deal is with Iran. We had large bipartisan majorities in both the House and the Senate to vote it down. If the president had followed the text of the Constitution and submitted it as a treaty, we wouldn't be in that agreement now. But it had an important impact. It helped create a chilling effect for international businesses and banks and certainly American businesses and banks. There's not a gold rush going on in Iran right now and there's more opportunity in the future to unwind that deal so we don't see Iran with a nuclear weapon.

But even your nominee now – Trump – has said he wouldn't rip up that deal?

Well, Donald Trump, like all 16 [other] candidates and every Republican and many Democrats in the Senate and House all said it was a terrible deal, and all said it was not in U.S. national security interests. Now we don't know what the world's going to look like come January. But at a minimum, the next president should demand much stricter terms for Iran to remove their centrifuges, to remove more stockpiles of uranium and other elements of a nuclear weapons program that they don't need.

If Trump called you for advice on national security issues, what would you tell him?

Well, I'd certainly advise him. I'd advise anyone who asked me for that. The most immediate thing I would say that we need to do to restore our capabilities around the world is an emergency supplemental spending bill for our military next year. If you extrapolate out what [former Secretary of Defense] Bob Gates predicted we would need in 2017, we're probably somewhere between $80 and $100 billion short and you see that all around the world. In the end, there's a lot of stuff to change on our foreign policy, but foreign policy without military capability is largely empty.

It's May of 2016, what are the chances you see yourself running for president in 2020?

(Laughs) We haven't even gotten our nominees yet in this presidential cycle, so I don't want to speculate about the future. All I'm focused on now is making sure we keep the Senate in Republican hands.

But what do you get out of being here?