Poland will not send troops to Iran as the conflict does not directly affect its security, Prime Minister Donald Tusk said on Tuesday, adding that the United States and other powers understood Warsaw's decision.

President Donald Trump called on allies over the weekend to help secure the Strait of Hormuz as Iranian forces continue attacks on the vital waterway amid the U.S.-Israeli war on Iran, now in its third week.

Poland's government "does not plan any expedition to Iran, and this does not raise any doubts on the part of our allies," Tusk said before a government meeting.

He said this covered Poland's land, air and naval forces, which are still being built up in the face of the conflict over the border in Ukraine.

Tusk said securing the Baltic Sea remained a central element of Poland's strategy.

A number of other U.S. allies, including Germany, Spain, and Italy, have said they have no immediate plans to send ships to help reopen the Strait of Hormuz, which Iran has effectively shut with attacks and threats of attacks.