A broadening of US sanctions on tankers that haul Iranian crude has jammed a crucial cog of the trade, slowing the delivery of oil from the OPEC producer to its most valuable customer: China.

Oil was steady after three days of advances, as the US looks increasingly likely to further sanction Russia’s and Iran’s energy sectors.Most Read from BloombergBrace for a Nationwide Shuffle of Corporate HeadquartersAmerican Institute of Architects CEO ResignsCloud Computing Tax Threatens Chicago’s Silicon Valley DreamSan Francisco,