Estonian poet and academic who rose to literary prominence in the 1960s. He taught in the Modern Languages and Literatures Department of the University of Oklahoma.
He lived in Estonia and Germany before moving to the United States in 1949.
In 1967, he became Editor-in-Chief of an international quarterly publication called World Literature Today.
He was married to Latvian poet Astrid Ivask.
He was a contemporary of American writer Joseph Heller.