WASHINGTON (Reuters) - US President Barack Obama on Tuesday sought to control damage from an explosive leak of Afghan war documents, saying he was concerned about the disclosure but it revealed little that was not already known. Defending his strategy for the unpopular war after the unauthorised release of some 91,000 classified reports, Obama insisted the leak underscored the need to stick to his approach and he urged Congress to approve critical additional funds for the war effort. While Im concerned about the disclosure of sensitive information from the battlefield that could potentially jeopardize individuals or operations, the fact is, these documents dont reveal any issues that havent already informed our public debate on Afghanistan, Obama told reporters after a meeting with congressional leaders. The Obama administration has scrambled in response to the leak of military records that painted a grim picture of the US-led war in Afghanistan and raised new doubts about key ally Pakistan. Obama said the reports point to the same challenges that led me to conduct an extensive review of our policy last fall. For seven years, we failed to implement a strategy adequate to the challenge in this region, the region from which the 9/11 attacks were waged and other attacks against the US and our friends and allies have been planned, Obama said. Thats why weve substantially increased our commitment there, insisted on greater accountability from our partners in Afghanistan and Pakistan, developed a new strategy that can work and put in place a team, including one of our finest generals, to execute that plan, he said. Now we have to see that strategy through and, as I told the leaders, I hope the House will act today to join the Senate, which voted unanimously in favour of this funding, to ensure that our troops have the resources they need and that were able to do whats necessary for our national security.