WASHINGTON, June 27 - The United States is preparing sanctions aimed at specific areas of the Russian economy, including energy and technology, as the administration of U.S. President Barack Obama readies the next steps to pressure Russia over the Ukraine crisis, but further U.S. action may await the results of a European Union summit, the Bloomberg news agency reported.

Sources cited by the agency believe it is unlikely that Obama will act alone if the European countries do not support the more aggressive sanctions.