De Maiziere complained that information that had been requested of Washington by the German government about the actions of the National Security Agency (NSA) was "to date, insufficient."

Speaking to the news magazine Der Spiegel, the minister complained that Berlin's fears about the extent of the agency's operations - as revealed by whistleblower Edward Snowden- had not been allayed.

"If two thirds of what Edward Snowden maintains is true, or what has been put forward pertaining to him as a source, then I can only come to one conclusion," de Maiziere said on Saturday, ahead of the magazine's publication. "The US actions are beyond all measure."

'Expectations low'

Chancellor Angela Merkel is due to visit US President Barack Obama in Washington in May. However, de Maiziere said he held out little hope of concrete results.

After the revelations about US mass surveillance, with data about the electronic communications of million of Europeans being examined by US operatives, Germany has been calling for a "no-spy deal."

At the end of February, the German government signaled it was not confident of a deal "in the immediate future."

In his interview, de Maiziere said that "according to everything I have heard," nothing would happen.

"My expectations about the success of further talks are low," said the minister.

Revelations about the NSA's spy programs were first published in the Guardian and Washington Post in June, sparking concern about the agency's level of access to personal accounts with data collection networks such as Yahoo, Google and Facebook. It was also revealed that US intelligence have been spying on Merkel's own cell phone, and subsequently the communications of at least one minister.

rc/crh (AFP, dpa)