WASHINGTON - US President Barack Obama told British Prime Minister David Cameron on Thursday that the United States "values a strong UK in a strong European Union," the White House said.

US President Barack Obama plays table tennis against students with British Prime Minister David Cameron at the Globe Academy in London in this May 24, 2011 file photo. [Photo/Agencies]

Cameron, who has faced calls from some in his own party for a referendum on whether Britain should exit the EU, postponed on Thursday a much-anticipated speech on Britain's future role in the EU because of the hostage crisis at an Algerian gas plant where Britons and Americans are believed to be among those held.

Obama and Cameron, in a telephone call, also consulted on the Algeria hostage situation, and the leaders expressed support for the French military operation against Islamist militants in Mali, the White House said.

"The prime minister set forth his thinking on UK-EU relations in light of his upcoming speech," the White House said.