WASHINGTON (Reuters) - Ukrainian President Volodymyr Zelenskiy will deliver an address on Tuesday evening at the Ronald Reagan Institute in Washington, the institute said in a statement, as the Ukrainian leader looks to drum up more support for the war against Russia's invasion during this week's NATO summit.

"President Reagan understood the Soviet Union and Russia. He knew that free countries must stand together with confidence whenever tyranny is on the move," Oksana Markarova, Ukraine's ambassador to the United States, said in the statement, referring to the Republican U.S. president from 1981 to 1989.

NATO is not expected to invite Ukraine to become a member at this year's July 9-11 gathering. Many NATO countries want to state that Ukraine's path to membership is "irreversible" but alliance members are still wrangling over the summit declaration.

(Reporting by Phil Stewart; Editing by Chizu Nomiyama)