By Allison Martell
(Reuters) - The chief executive of Alcoa Inc
Chief Executive Klaus Kleinfeld was to participate in the event, which runs May 22-24, according to the business forum's website, which said the event is "under the auspices" of the Russian president.
"In light of the U.S. government's requirements, Alcoa has adjusted its attendance at the St. Petersburg International Economic Forum and will participate via its most senior Russian executives," Alcoa said in an emailed statement.
Asked whether U.S. officials had urged Alcoa not to send its top executive to the event, a company spokeswoman confirmed that they had.
At Thursday's daily White House press briefing, spokesman Jay Carney was asked about efforts by administration officials to urge executives not to attend the forum.
Carney confirmed officials had been discussing the event with business leaders, and had made it clear that attending would not be appropriate given "flagrant violations of a sovereign nation's territorial integrity."
The forum is Russia's main annual economic conference and is used to attract new investors into the country.
The United States and the European Union imposed more sanctions on Russia this week as part of their drive to put pressure on Moscow over the annexation of Crimea and what they see as direct support for pro-Russian separatists that have seized public buildings across eastern Ukraine.
(Editing by Ros Krasny, Steve Orlofsky and Meredith Mazzilli)