WASHINGTON » President Barack Obama today called reports that the Internal Revenue Service targeted conservative groups "outrageous" and said anyone responsible should be held accountable. He pushed back strongly against fresh Republican criticism of the administration’s handling of last year’s deadly Benghazi attacks, calling it a "political sideshow."

The president was dogged by the persisting political controversies as he tended to diplomatic duties during a visit with British Prime Minister David Cameron.

Obama acknowledged that people are properly concerned about acknowledgements from the IRS that conservative political groups were targeted during the 2012 campaign to see if they were violating their tax-exempt status. But he angrily dismissed continued questions over September’s insurgent attack in Libya that killed Ambassador Chris Stevens and three other Americans.

"There’s no there there," Obama said.

"The fact that this keeps on getting churned up, frankly, has a whole lot to do with political motivations," he said.

Cameron and Obama had a meeting in the Oval Office before appearing before the media in the East Room to take questions.

The two leaders said they had discussed several pressing international issues, including the Mideast peace process, trade and preparations for a coming summit of the world’s leading industrial nations in Northern Ireland. They said they were committed to working together to keep pressure on Syria’s President Bashar Assad and assist the opposition in a protracted civil war. Cameron said, "There is no more urgent international task."