Democratic presidential candidate John Kerry (search) said Wednesday that the Bush administration's response to abuse of Iraqi prisoners by some U.S. soldiers has been "slow and inappropriate."

"I think the world needs to hear from the president that the United States of America regrets any kind of abuse of this kind or any kind of effort like this," Kerry said at his first news conference in three weeks. "Because we have to show the world that we're willing to correct our own mistakes."

The Massachusetts senator spoke to reporters on the same day that Bush told television stations broadcast to the Arab world that the treatment of Iraqi prisoners was "abhorrent" but stopped short of apologizing.

Bush said there will be investigations and individuals will be brought to justice. Kerry echoed the call for an investigation and declined to say that an apology is needed pending the outcome.

"The president of the United States needs to offer the world an explanation and needs to take appropriate responsibility," he said. "And if that includes apologizing for the behavior of those soldiers and what happened, then we ought to do that."

Photographs of U.S. soldiers gloating over naked detainees in demeaning positions have been broadcast around the world and sparked anger and protests in Arab countries. Kerry said the abuse has been a disservice to U.S. troops and could put them in further jeopardy of a terrorist attacks.

"The horrifying abuse of Iraqi prisoners which the world has now seen is absolutely unacceptable and inexcusable," he said. "And the response of the administration, certainly the Pentagon, has been slow and inappropriate. I believe the president needs to guarantee that the world is going to have an explanation."

Kerry singled out Defense Secretary Donald H. Rumsfeld and the chairman of the Joint Chiefs of Staff, Gen. Richard Myers, for failing to act earlier on the abuse allegations.

"I want to know, as I think Americans do, is this isolated? Does it go up the chain of command? Who knew what when?" Kerry said. "All of those questions have to be answered, so I don't want to shoot from the hip on that."

Kerry spoke to reporters in the midst of a three-day education tour with stops in Minnesota, New Mexico and California. The Kerry campaign, lagging behind Bush on the ground game, is just beginning to bolster its state operations, sending 68 organizers to 14 states this week.

Kerry celebrated Cinco de Mayo (search) — one of Mexico's most important national holidays — at Woodrow Wilson High School, where he criticized Bush's education policies. He sprinkled his remarks with the Spanish that he's been learning on cassette tapes.

Bush "promised in the No Child Left Behind Act (search) that billions of dollars would be coming to America. El rompio las promesas," Kerry said, then translated. "He broke his promises to America."

Kerry honored the troops serving in Iraq and Afghanistan.

"We pray that the next Cinco de Mayo, they will celebrate here in the streets of the United States of America," he said.

Kerry also was meeting privately with Los Angeles Cardinal Roger Mahony (search). Kerry, a Roman Catholic who has faced some criticism from church leaders for his support of abortion rights, would not answer questions about what he would discuss with the cardinal.