The best way for the United States to handle Iran in the wake of Thursday's airstrike – which killed top Iranian Gen. Qassem Soleimani – is by maintaining a maximum pressure campaign, Gen. Jack Keane said Friday.

Appearing on "America's Newsroom" with host Sandra Smith, Keane said that President Trump's strategy is effective because it's a departure from the Obama administration's "appeasement policy." He said that Iran-backed attacks on Americans were a "red line" for Trump and he responded when such attacks occurred in Iraq.

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"After all, the Iranians have been escalating for 18 months in the Middle East to create a crisis so that pressure is put on the United States to stop the sanctions," he said. "And they've been disrupting oil. They attacked...the largest oil fields in the world, the Persian Gulf tankers disruption, et cetera. They shot down a U.S. drone and we did not retaliate."

"But the president showed restraint and he put a red line out there, Sandra. He said, 'Look it, if you kill Americans I'm going to respond.' And, when that took place, this president responded," Keane stated, adding that Soleimani was "about to do it again," meeting in Iraq with a deputy commander of an Iran-backed militia.

In an earlier interview on "Fox & Friends," Secretary of State Mike Pompeo alleged that the administration's moves on the chessboard would eventually lead to "success and stability" in the Middle East.

Keane agreed with Pompeo saying that this is "our best chance" to create that success and stability.

He told Smith that the president "looked at" the Obama administration's dealings with Iran – including the now-dissolved Iran Nuclear Deal – and said, "'No, we are not continuing down that path.'"

"In concert with our allies," he continued, "strategically, the policy decision was [that] we are going to confront Iran. Not with bullets; we are going to do is economically and diplomatically. And, that is what has so frustrated this regime."

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Keane said keeping up the maximum pressure campaign is the best course of action for the U.S. now.

"I believe this is the only path we can get to curbing their aggressive and malign behavior that's been going on for 40 years. All other attempts have failed. This is the best shot we've got to stop this aggression."