Miliband, who is visiting the United States this week, said Washington must remain committed to global trade "in a very fundamental way."
Amid signs that Britain is troubled by calls from Barack Obama for measures such as trade tariffs on China, Miliband said "American internationalism has been a feature of all periods of global progress... It's absolutely clear that the world needs an America that's engaged with the global trading system in a very fundamental, very committed way."
"The problem is not too much trade, the problem is too little trade. That is our position as a British government, and it will be articulated clearly and consistently," Miliband said.
According to the report, Miliband, who is meeting advisers to the presidential rivals during his trip to the U.S., said he did not want to criticize any of the candidates in the contest, but that Britain would be forthright in arguing against any shift by the U.S. towards protectionism.
Referring to mistakes over the U.S.-led invasion of Iraq, Miliband argued that it was "very, very important for the next decade, learning from the last in foreign policy, that we make the right decisions."
But he also argued that Europe must work out how it can be a "good and better partner" to the new president "because no big problems get solved without the United States."
Miliband emphasized that Britain no longer viewed its relationship with the U.S. as one that automatically relegated the European Union to second place, adding that there was now considerable cooperation between London, Paris and Berlin on transatlantic policy.
"We've got institutions in Paris and Berlin that want to work closely with the Americans... There's a transatlantic project that spans other European countries as well... We're always coordinating activities." said he.
