Prime Minister Scott Morrison said Canberra would commit a frigate, patrol plane and specialist defense force personnel to the security flotilla escorting commercial shipping from Iranian attacks.
Without offering specifics, the president says he is increasing sanctions as Washington accuses Tehran of downing a U.S. drone and attacking foreign-owned oil tankers in the Gulf of Oman.
Pointing to a U.S. military video, Trump maintained: "Iran did do it." Meanwhile, the president of the Japanese company operating one of the tankers says he doesn't believe a mine or torpedo was used.
Pompeo said Iran is using "terror, bloodshed and extortion" in an attempt to pressure the U.S. to ease what he described as a "maximum pressure" campaign against Iran.