WASHINGTON — The Environmental Protection Agency and the Department of Agriculture jointly proposed new rules on Friday that would increase ethanol consumption at the expense of oil refineries to help corn and soybean farmers buffeted by President Trump’s trade wars.

The plan would overhaul the system of quotas for ethanol, a fuel that is made from corn and other crops , as they blend their fuels. Its overall goal is to increase the sale of the biofuel beyond the current mandate of 15 billion gallons annually.

It also will ensure that a gasoline blend made of 15 percent ethanol will be available at the pumps already in place at most gas stations, rather than requiring the installation of new pumps. The proposal also includes trade measures to increase the access of ethanol to foreign markets.

The move is widely viewed as an effort to relieve pressure on farmers at a time when the Trump administration is escalating its trade war with China and Europe.