Japan’s Mitsui O.S.K. Lines (MOL) said three of its vessels that transited the Strait of Hormuz and exited the Gulf in April did not pay transit fees, sticking to a principle of navigation under international law, Reuters reports.

Tehran has proposed fees or tolls on vessels passing through the Strait, in its proposals to end the war with Israel and the United States.

The company does not intend to pay such fees in future, a company spokesperson told Reuters.