Trust, but verify

The phrase became internationally known in English after Suzanne Massie, a scholar of Russian history, taught it to Ronald Reagan, then president of the United States, who used it on several occasions in the context of nuclear disarmament discussions with the Soviet Union.

Suzanne Massie, an American scholar, met with Ronald Reagan many times between 1984 and 1987 while he was President of the United States.

"[2] The proverb was adopted as a signature phrase by Reagan, who used it frequently when discussing United States relations with the Soviet Union.

[11] In 2000, David T. Lindgren's book about how interpretation, or imagery analysis, of aerial and satellite images of the Soviet Union played a key role in superpowers and in arms control during the Cold War was titled Trust But Verify: Imagery Analysis in the Cold War.

For example Vladimir Dal's vast collection Sayings and Bywords of the Russian people [ru] does not contain anything similar to the proverb.