March 16 (UPI) -- President Donald Trump late Sunday demanded nations that rely on oil shipped through the Strait of Hormuz join his coalition to police the important transit route as oil prices surge worldwide.

The American president has been seeking to cobble together a coalition of nations to protect shipping vessels in the strait located between Oman and Iran. Iran early this month announced it was closing the maritime chokepoint through which about 20% of all oil travels in response to the war launched Feb. 28 by the United States and Israel.

Iranian officials have indicated that ships connected to the United States and Israel would not be permitted to pass through the strait, while other countries are in talks with Tehran to secure safe passage.

The war has seen the price of a barrel of oil rise from an average of $71 on Feb. 27 to $104 on March 9, according to the global benchmark Brent crude oil spot price, the U.S. Energy Information Administration said in its March energy outlook report.

Speaking to reporters aboard Air Force One, Trump wouldn't name the countries his administration was speaking to about joining the coalition, but said they were in contact with about seven nations reliant on Middle Eastern oil.