"The Chancellor of Germany, Friedrich Merz, thinks it's OK for Iran to have a Nuclear Weapon. He doesn't know what he's talking about!" Trump said in a post on his Truth Social network.

Merz made the comments Monday during a visit to a school in Marsberg, western Germany.

"The Americans obviously have no strategy. And the problem with such conflicts is always that you not only have to get in, you also have to get out again," Merz said.

"We saw that in a very painful way in Afghanistan for 20 years. We saw it in Iraq," he added.

"So this whole thing is, as I said, at the very least ill-considered."

Merz said he could not see "what strategic exit the Americans are going to choose, especially since the Iranians are obviously negotiating very skillfully -- or very skillfully not negotiating."

"An entire nation is being humiliated there by the Iranian leadership, above all by these so?called Revolutionary Guards," he said.