America is refusing to enter a bilateral no-spy agreement with Germany and has declined to rule out bugging the calls of German political leaders in the immediate future, according to reports in the German media.

Last October, revelations that the National Security Agency had been bugging Angela Merkel's mobile were met with outrage in Berlin and apologetic soundbites from Washington.

President Barack Obama had reportedly assured the German leader that the US "is not monitoring and will not monitor the communications of chancellor Merkel". Barely three months on, the mood seems to have changed.

Initial hopes in Germany that the US would enter into some kind of non-spying pact similar to the one between America and Britain have been dashed, according to information obtained by Süddeutsche Zeitung newspaper.

"We are not getting anything," the newspaper quotes a source from within the German foreign intelligence agency. "The Americans have lied to us," said another source.

As well as refusing to inform German authorities of when the NSA had been bugging the chancellor's mobile phone, the US is not commenting on plans for current or future surveillance activities in relation to German political leaders.

A request for access to what is assumed to be a surveillance centre in the top floor of the US embassy next to Berlin's Brandenburg Gate has also been rejected.

The German government has told the Obama administration it would consider such a "nest of spies" a breach of the Vienna Convention on Diplomatic Relations.

Talks about a surveillance agreement between Germany and the US started months before it emerged that Merkel's mobile phone had been targeted. In August 2013, the German government answered an official query on the subject, saying there had already been a verbal agreement and that a pact had been suggested by the US.

Government spokespeople on both side of the Atlantic have so far refused to comment on the newspaper reports. The official line from within the German chancellory is that the government is still hoping for an agreement with the US in the next few months.