European Council President Herman Van Rompuy addresses a news conference at an European Union leaders summit in Brussels, Oct 25, 2013. [Photo/Agencies]

BRUSSELS - The European Union will seek talks with the US over the alleged spying on its European allies under a Franco-German initiative, following further exposure of reported surveillance activities.

"All 28 EU member states agreed on the nature of the initiative," Herman Van Rompuy, President of the European Council, said in the early hours of Friday at a press conference following the first day of a two-day summit.

Van Rompuy told reporters that Britain had agreed with the initiative, saying: "The UK has a special relationship (with the US), but they are completely on board."

France and Germany proposed talks with the United States to seek an agreement or an understanding with regards to secret service, and invited all other EU member states to join, Van Rompuy said.

The European leaders gathered to convene the summit Thursday on the back of reports of the US National Security Agency (NSA) spying on French citizens' communications and eavesdropping on German Chancellor Angela Merkel's mobile phone.

On Wednesday, Berlin voiced its anger at the possible US spying on Merkel, saying it would be "a serious breach of trust" if confirmed.

In an unusually sharply-worded statement, Merkel's spokesman Steffen Seibert said Merkel had called US President Barack Obama on Wednesday after receiving information about the alleged spying.

"Among close friends and partners as Germany and the US have been for decades, there should be no such monitoring of communications of a head of government," Seibert said.

Merkel also called on Washington to clarify the extent of possible surveillance activities in Germany and to give answers to questions that the German government asked months ago.

However, the White House denied tapping Merkel's mobile phone, saying that the United States "is not monitoring and will not monitor" the communications of the chancellor, according to spokesman Jay Camey.

Meanwhile, French Foreign Minister Laurent Fabius on Tuesday met with US Secretary of State John Kerry, reiterating France's request for an explanation regarding the "unacceptable" spying practices, said the French Foreign Ministry in a statement.

France's newspaper Le Monde reported Monday that the NSA had secretly monitored 70.3 million phone communications in France from December 10, 2012 to January 8 this year.

French President Francois Hollande expressed Monday his "strong condemnation" of the monitoring during a phone call with Obama, branding it as "unacceptable" between friends and allies, said the French Presidency Elysee.

Hollande also hoped "a bilateral cooperation could be carried out between French and American intelligence services in order to figure out more clearly" the alleged spying practices of the NSA, French government spokesperson Najat Vallaud-Belkacem told a press conference, saying the proposal "was accepted by (US) President Barack Obama."

In response to the alleged snooping, European lawmakers Wednesday urged the EU to deny the US access to the global banking database SWIF, following revelations concerning the NSA's possible tapping of EU citizens' bank data, said a statement issued by the European Parliament.

Germany's Spiegel earlier reported the NSA illegally accessed the email account of then Mexican President Felipe Calderonn in 2010, citing documents from former NSA contractor Edward Snowden.

Other revelations from Snowden showed the NSA had also spied on Brazilian President Dilma Rousseff and current Mexican President Enrique Pena Nieto before he was elected in June 2012.