Frank Ruggiero, who last month replaced the late Richard Holbrooke as acting representative for Afghanistan and Pakistan, will travel to those countries later this week, a US official said. His trip comes before world leaders from South Asia and beyond attend a memorial ceremony for Holbrooke on January 14, State Department spokesman Philip Crowley told reporters. Crowley said Ruggiero will "focus on preparations" for talks next month in Washington involving top US, Afghan and Pakistani officials who are trying to stabilize the region. The acting envoy will meet government officials, representatives of civil society, and the media during a trip that Holbrooke had planned to make before he died on December 13 following a torn aorta. Ruggiero will reaffirm US commitment "to the people of Pakistan and will continue to support Pakistan's efforts to ensure greater peace, security and stability in the region, now and in the future," Crowley said ."And he will also reiterate in Afghanistan the president's commitment to transition to full Afghan lead for security that will begin this year and conclude in 2014," he added.Officials in Islamabad said Pakistani President Asif Ali Zardari will visit Washington next week, and stay on to attend the Holbrooke memorial service which Crowley said will take place January 14 at the Kennedy Center.Zardari will meet Clinton during his visit, they said."There are a number of world leaders who will be coming to the memorial, and I would expect that there would be some meetings around that," Crowley said.