WASHINGTON, March 17 (Reuters) - The Trump administration is seeking other sources of fertilizer amid the ongoing Iran war's shipping constraints, including from Venezuela and possibly Morocco, White House economic adviser Kevin Hassett said on Tuesday.

   "We've ... established licenses for Venezuela to produce more fertilizer. We've had discussions with Morocco," he said on CNBC's "Squawk Box" program, calling it "an insurance policy against disruption" for U.S. farmers.

"I'm not saying that we can eliminate what disruption there is so far, but we can minimize it," Hassett told CNBC in the interview.

Fertilizer supplies have shrunk as the U.S.-Israeli war against Iran cut off critical nitrogen fertilizer supplies from the Gulf to the world's farmers, sending prices spiking by more than one-third in recent weeks.

European Union foreign policy chief Kaja Kallas has floated the idea of replicating a U.N.-brokered deal that got grain out of Ukraine during wartime. It allows Ukraine to export grain, foodstuffs and fertilizers through the Black Sea, without civilian ​vessels coming under attack by Russia. She said she had spoken to U.N. Secretary General Antonio Guterres about the idea and the U.N. was "working on this".