European Union leaders are meeting at a summit in Brussels amid a trans-Atlantic row over the secret monitoring of phone calls by U.S. intelligence services.
The two-day summit on October 24-25 was initially planned to discuss consolidating Europe's fragile economic recovery, and the flow of illegal migrants from North Africa and the Middle East.
But the talks risked being overshadowed by the spying allegations after it emerged that U.S. intelligence services may have been monitoring German Chancellor Angela Merkel's mobile phone.
Arriving for the summit on October 24, merkel said trust has to be reestablished between the European Union and the United States.
"Ever since we have been talking about the [U.S. National Security Agency], I have made it clear, also to the American president, that [this is] absolutely not done among friends," she said. "I said this in June when [U.S. President Barack Obama] was in Berlin...and again yesterday in a telephone call [to him]. And this is in the interest of all German citizens -- it's not about me -- but mainly it is for all citizens; we need to have trust among our allies and partners. And such trust must be newly restored."
U.S. President Barack Obama assured Merkel on October 23 that U.S. agencies were not monitoring her mobile phone, but the White House declined to clarify whether her communications had been monitored in the past.
On October 24, White House spokesman Jay Carney refused to comment on the case.
"We have direct communications through diplomatic channels at the highest level and other levels with our very close allies in Germany," he said. "And the United States greatly values our close cooperation with Germany on a broad range of shared security challenges and, as the President [Barack Obama] has said, the United States is reviewing the way that we gather intelligence to ensure that we achieve that balance that I spoke about. Beyond that I'm just not going to -- in this case or in other cases -- get into specific allegations that have been made in published reports."
The allegations Merkel's mobile phone may have been monitored came just days after French media reports that the U.S. National Security Agency (NSA) had monitored millions of French phone calls.
French President Francois Hollande has said he wants the issue put on the agenda at the EU summit.
Much of the disclosures about secret U.S. electronic surveillance programs came from former NSA contractor Edward Snowden.
With reporting by Reuters and dpa