WASHINGTON — President Barack Obama scoffed at the idea that he should apologize to Iran’s leaders for criticizing their violent crackdown on demonstrators and said President Mahmoud Ahmadinejad has operated outside of “international norms” and now must answer to his people.

Standing next to German Chancellor Angela Merkel, Obama said the United States and Germany share “one voice” in condemning the Iranian effort to crush dissent. He said Iran’s leaders cannot hide the “outrageous” behavior of clamping down violently on their people.

“We see it and we condemn it,” Obama said.

Obama spoke in a joint White House appearance with Merkel after they conferred privately. The two leaders have met three times since Obama took office, allies linked by such international troubles as the war in Afghanistan and a worldwide recession.

Keeping pressure on Iran, Obama hailed the Iranian people.

“Their bravery in the face of brutality is a testament to their enduring pursuit of justice,” Obama said.

“The violence perpetrated against them is outrageous. In spite of the government’s efforts to keep the world from bearing witness to that violence, we see it and we condemn it.”

Merkel backed Obama’s stand. And she said Iran must be kept from getting a nuclear weapon.

Iran’s violent postelection chaos has captured the world’s attention and elicited increasingly sharp condemnations from Obama. Iran’s ruling clergy have widened the clampdown on the opposition since a bitterly disputed June 12 presidential election, and scattered protests have replaced the initial mass rallies.

At least 17 people have been killed in a state-led crackdown on protesters.

Incumbent Ahmadinejad was proclaimed the landslide winner over opposition leader Mir Hossein Mousavi.

Obama’s comments today got more direct about the two leaders.

He said Mousavi had captured the spirit and imagination of the Iranian people who want a freer society.

And he dismissed statements by Ahmadinejad, who on Thursday compared Obama to former President George W. Bush. Obama said he is not meddling in Iran’s affairs but rather calling for principles to be upheld that reflect “universal norms, international norms.”

The Iranian leader has told Obama to “show your repentance.”

Obama said he doesn’t take such statements seriously.

“He might want to consider looking at the families of those beaten or shot or detained,” Obama said. “That’s where Mr. Ahmadinejad and others need to answer their questions.”

Obama said it is too soon to tell how potential, direct contact between the United States and Iran over a nuclear dispute will be affected by recent events.