US Secretary of State Mike Pompeo is seeking support from a united international community by working to convince leaders that Iran was behind attacks on shipping in a key Middle East oil route.
Pompeo said there was "unmistakable" evidence that Iran was to blame for the attacks on two oil tankers, but was emphasising international diplomacy over any military response.
"We are going to work to build out a set of countries that have deep vested interest in keeping (the Strait of Hormuz) open, to help us do that," he said.
Iran has denied being involved in the attacks and accused the US of promoting an "Iranophobic" campaign against it.
Pressed on whether new US military deployment to the region was possible, Pompeo said that remained among the options that President Donald Trump may consider to keep oil tankers moving from the Middle East.
Trump last year withdrew the US from an international agreement, signed in 2015 by then president Barack Obama, to limit Iran's nuclear program.
He reinstated economic sanctions and recently ended waivers that allowed some countries to continue buying Iranian oil.
That has deprived Iran of oil income and has coincided with what US officials said was a surge in intelligence pointing to Iranian preparations for attacks against US forces and interests in the Gulf region.
Pompeo stressed that the US gets relatively little of its energy supplies through the strait. The US Energy Information Administration says 16 per cent of US petroleum imports came from the Persian Gulf countries in 2018.
By contrast, about 80 per cent of oil through the shipping passage supplies energy-hungry countries in Asia, including China, Japan, India and South Korea.
German Foreign Minister Heiko Maas urged caution on Monday, noting that Berlin has not yet come to a final conclusion on who is to blame.
Australian Associated Press