Following last week's swine flu outbreak, which is believed to have started in Mexico before spreading to the U.S. and other countries, Russia imposed a ban on raw pork imports from a number of U.S. states as part of emergency measures to try and contain the disease.
However Gary Locke reiterated world and U.S. health official advice on Friday that swine flu cannot be spread by food.
And Locke said in a letter addressed to deputy prime minister, Alexei Kudrin, and China's trade minister, Chen Deming: "Government actions during this time of economic uncertainty and international concern about influenza must be based on scientific evidence. There should be no restrictions on trade without cause."
According to the World Health Organization, the swine influenza virus is killed by cooking temperatures above 70 degrees Celsius (160 degrees Fahrenheit).
The swine flu outbreak which has caused worldwide panic with at least 331 people diagnosed with the A/H1N1 virus.
Mexico's health minister, Jose Angel Cordova, said that number of people infected with swine flu had risen to 397 with 16 confirmed deaths.
Mexico has introduced a five-day closure of restaurants, cafes, bars, tourist attractions and public place in Mexico City and other town and cities to try and contain the spread of the disease.
Russia and China import around 20% of all U.S. pork exports.
