Mehr news agency reported Iran's Supreme Joint Military Command said closure of the Strait of Hormuz is the first step and warned it would take further measures if 'aggression continues'.

The dollar index, which measures the US dollar against six major currencies, fell 0.12% to 100.729 at the New York FX close on the 19th. EUR/USD rose to 1.1477 from 1.1459; GBP/USD rose to 1.3234 from 1.3203. USD/JPY fell to 161.26 from 161.68. USD/CHF rose to 0.8066 from 0.8051; USD/CAD rose to 1.4174 from 1.4140; USD/SEK fell to 9.5742 from 9.5874.

UK media reported on the 19th that Iran’s Persian Gulf Strait Administration has issued a document requiring all vessels to carry insurance approved by the agency to transit the Strait of Hormuz. The document, circulated among shipping managers and reported by the FT, says “all vessels must hold a valid insurance policy approved by the Persian Gulf Strait Administration”; the cover is currently “free” within the period set out in the US‑Iran memorandum of understanding, but the administration “reserves the right to charge premiums in future.”