WASHINGTON - While announcing his plan to withdraw most American troops from Iraq in 18 months, President Barack Obama said Friday that his Administration was now refocusing on Al-Qaeda in Afghanistan and Pakistan. "We have also taken into account the simple reality that America can no longer afford to see Iraq in isolation from other priorities: we face the challenge of refocusing on Afghanistan and Pakistan; of relieving the burden on our military; and of rebuilding our struggling economy - and these are challenges that we will meet," he said in a live-broadcast speech delivered at the Marine base of Camp Lejeune in North Carolina. "This reflects a fundamental truth: we can no longer deal with regional challenges in isolation - we need a smarter, more sustainable and comprehensive approach. That is why we are renewing our diplomacy, while relieving the burden on our military, the US President said. "That is why we are refocusing on Al-Qaeda in Afghanistan and Pakistan; developing a strategy to use all elements of American power to prevent Iran from developing a nuclear weapon; and actively seeking a lasting peace between Israel and the Arab world. And that is why we have named three of America's most accomplished diplomats - George Mitchell (for Middle East), Dennis Ross (for Persian Gulf) and Richard Holbrooke (for Pakistan and Afghanistan) - to support Secretary (Hillary) Clinton and me as we carry forward this agenda".