The United States on Thursday imposed sanctions on companies based in China and elsewhere over their alleged involvement in sales of Iranian petroleum and petrochemical products. The move came as Tehran continues to accelerate its nuclear activities in violation of a 2015 multilateral deal, under which Iran agreed with the United States and five other major powers to limit its nuclear program in return for sanctions relief. The State Department targeted two entities based in China, including Zhonggu Storage and Transportation Co., which operates a commercial crude oil storage facility for Iran…