US Secretary of State Mike Pompeo thanked the Peruvian government for taking a stand against Venezuelan President Nicolas Maduro on his visit to Lima on Saturday.
The top US diplomat started by saying Peru had shown "generosity" in hosting three quarters of a million Venezuelan migrants.
"We want to ensure all Peruvians that you are not shouldering this burden alone," he added.
Under questioning from a journalist, Pompeo then blamed Maduro and his allies for the refugee problem.
"A hundred per cent of the refugee challenge that is faced by Peru and Colombia is the direct result of Russians, the Cubans, and Nicolas Maduro," he argued.
Pompeo visit to Peru is part of a regional tour including stopovers in Chile, Paraguay, and Colombia.