By Trevor Hunnicutt and Michael MartinaWASHINGTON (Reuters) -The United States is sounding out close allies about the possibility of imposing new sanctions on China if Beijing provides military support to Russia for its war in Ukraine, according to four U. One source said the administration wanted to first raise the idea of coordinated sanctions and "take pulses" in the event that any shipments are detected to Russia from China, which declared a "no limits" partnership shortly before the invasion on Feb. "Then the administration can send messages to China in public and in private, with the latter being more explicit, that the U