MOSCOW, Oct. 15 -- Russia's deputy prime minister says no contract has yet been signed to ship Russian diesel to the United States, five days after Donald Trump announced that the fuel was coming.

Alexander Novak told reporters at the Russian Energy Week forum in Moscow on Wednesday that "a contract should be made and loading of supplies should be provided. It will require some time," TASS reported. Contracts are being examined "at the level of ministries and companies," he said, and the Russian Energy Ministry and the US Department of Energy are looking for "an instrument" to support the supplies. The reports name no company on either side.

Kirill Dmitriev, the president's special envoy for economic cooperation, gave a faster clock. He...