The United States will suffer a sharp loss of influence in Europe if Americans withdraw their troops, West German Defense Minister Gerhard Stoltenberg says. ``In the past, American cooperation and influence on European policy was helpful, and in future, American policy and influence in Europe can be helpful,'' Stoltenberg said Tuesday evening. ``But without any soldiers or significant (numbers of) soldiers, your influence in all matters of security policy will sharply decline,'' he added. ``And I doubt whether this is desirable.'' Stoltenberg said in a speech before the American Institute for Contemporary German Studies of the Johns Hopkins University that Americans should maintain a substantial military presence for the foreseeable future. He said the United States might be able to reduce its forces in Central Europe beyond the 195,000 troops proposed by President Bush, if that could be coordinated with European allies and the Soviet Union. The defense minister met with Defense Secretary Dick Cheney earlier Tuesday, and they discussed German unification and other European issues, Pentagon spokesman Pete Williams said. A Pentagon source who spoke on background said the officials discussed problems with East-West talks in Vienna to cut conventional forces in Europe. He declined to say what the problems were. Stoltenberg called on the North Atlantic Treaty Organization to retain nuclear forces in Europe, but said their numbers should be greatly reduced.