Rep. Michael McCaul said Sunday that the U.S. should put more pressure on Russia that would force Russian President Vladimir Putin to negotiate an end to its war with Ukraine.

“I think we need to put tougher sanctions on Putin,” McCaul told ABC News’ “This Week” co-anchor Martha Raddatz. “If you want a serious negotiation, Putin has to have pressure put on him if he is going to make any concessions at all.”

It has been 4 1/2 years since Russia invaded Ukraine, but the war is escalating. Ukraine launched major attacks on Russia over the weekend, including in St. Petersburg, where Putin was present for an economic conference.

McCaul, a former chairman of the House Committee on Foreign Affairs, was one of 18 Republicans who voted Thursday to send aid to Ukraine and apply tougher sanctions on Russia, bucking House Republican leadership. McCaul was firm in his defense of Ukraine Sunday.

“Anytime I can help Ukraine and punish Putin, I’m in on that fight,” he said. “And the fact is that the Ukrainians are winning this fight, they’re taking back territory.”

McCaul said he is working with his colleagues in the Senate to introduce additional legislation to put tougher sanctions on Russia and Putin.

Here are more highlights from McCaul’s interview:

On 100 days of the Iran war

Raddatz: But do you really think it’s a cease-fire? They’re trading fire. Why is it still a cease-fire?

McCaul: That’s true. Defensive in nature. I agree with Gen. Jack Keane on this one. I think that — that, honestly, the Iranians are dragging this out. They want to drag this out closer to the midterm elections. I don’t think they’re negotiating in good faith. I mean, look, you’ve got to give, if you can —

Raddatz: Was the administration prepared for this, prepared for the Strait [of Hormuz] to be closed?

McCaul: It was obvious in the contingency plans that Iran had that capability, the capacity to close the strait. So, I know that had to be in their calculation. I think they thought the regime would implode after taking out the top leadership and the Ayatollah, and that didn’t happen. And so, you know, now, I — this is the first president in 50 years to actually try to do something about the problem. A nuclear Iran is not acceptable. We’ve always said that. Every president since 1979. I passed a resolution as chairman in the last Congress, say, by all means necessary, stop a nuclear Iran. So, he is taking action on the brink of that.

On the midterm elections

Raddatz: But he has also said in recent weeks that he doesn’t think about Americans’ financial situation as the war continues. Also said he doesn’t care about the midterms. Do you think that is true?

McCaul: Well, I think what he’s putting national security first. A nuclear Iran is not acceptable. I do think the American people, though, as they see high gas prices, affordability is going to be an issue in this midterm.

On Bill Pulte’s appointment to acting director of national intelligence

McCaul: I don’t believe he’s statutorily qualified. He doesn’t have any national security intelligence background. I applied for FISA warrants prior to Congress. If we go dark next week, right before the World Cup FIFA games, and the 250th anniversary, that would be the most grossly irresponsible thing I’ve seen Congress do in my 22 years in office.