By Maha El Dahan and Andrew Mills DOHA (Reuters) – Qatar has not approached its Asian customers over diverting gas to Europe, QatarEnergy chief and minister of state for energy Saad al-Kaabi told Reuters, adding that if Russia does not supply the region the gap could not be filled by one country. The United States, the world’s top producer of natural gas, has asked Qatar and other major energy producers to examine whether they can supply Europe should Russian flows be disrupted as a result of tensions with Ukraine. Earlier this week, a source told Reuters that Qatar would need U.S. help persua…