By BAGILA BUKHARBAYEVA The Associated Press Saturday, June 2, 2007; 7:18 AM MANAS AIR BASE, Kyrgyzstan -- When Defense Secretary Robert Gates visits next week, he'll find pressure from Russia and China , as well as some Kyrgyz officials, to close this Central Asian outpost of American military might. The Manas Air Base was set up to support U.S. operations in nearby Afghanistan , but it is part of high-stakes contest for political influence being played out across a region with vast natural gas and oil reserves. Small, poor and politically unstable, Kyrgyzstan is nevertheless being aggressively courted by the United States, Russia and China because of its strategic location. Russia also has an air base in this former Soviet republic of 5 million, part of a regional security treaty. But tensions surrounding the air base have hurt Washington's efforts to gain favor here. There have been disputes over payments, a fatal shooting and the mysterious reported kidnapping of an America...