India, April 15 -- The Trump administration will allow a temporary waiver permitting the purchase of certain Iranian crude oil to expire this weekend, signaling a continuation of its pressure campaign on Tehran.

In a social media post on Tuesday, the US Treasury Department said, "The short-term authorization permitting the sale of Iranian oil already stranded at sea is set to expire in a few days and will not be renewed," adding that it plans to use other available tools to sustain pressure on Iran.

The department also warned financial institutions of further action, stating, "Financial institutions should be on notice that the department is leveraging the full range of available tools and authorities and is prepared to deploy secondary...