German Chancellor Angela Merkel's office summoned the US Ambassador to Germany on Thursday to discuss new allegations about National Security Agency (NSA) spying, according to German media reports.Citing a German government source, German daily Frankfurter Allgemeine Zeitung said Peter Altmaier, chief of staff of Merkel's office, had "invited" US Ambassador John B. Emerson to meet for talks in the Chancellery.

According to the reports, Altmaier wanted to get information and clarification of the latest allegations over US tapping on German politicians and officials.

New documents released by WikiLeaks on Wednesday show that the NSA did not just tap Merkel's phone, but also eavesdropped on German ministers and senior officials.

Partly in collaboration with British secret services, the NSA reportedly targeted 69 phone numbers of the German government and showed particular interest in activities of the ministries of finance, economy and agriculture.

The new revelations have sparked criticism in Germany. Speaking to German Bild newspaper, German Finance Minister Wolfgang Schaeuble criticized the way in which the US intelligence services acted and called for clarification of the issue.

In addition, Germany's Public Prosecutor's Office is reportedly considering launching new investigation into NSA spying activities.