Turkey yesterday said it had summoned the US charge d'affaires in Ankara to demand an explanation over a report that Washington had spied intensively on Turkish leaders since 2006.
Der Spiegel reported that as well as sharing intelligence with Nato partner Turkey, the United States and its ally Britain had been conducting extensive electronic surveillance on the Turkish leadership.
The German weekly said its information was based on documents released by the fugitive former National Security Agency operative Edward Snowden who has taken asylum in Russia.
"The US charge d'affaires has been summoned to the foreign ministry to demand an explanation," Deputy Prime Minister Bulent Arinc said.
The new US ambassador to Turkey, John Bass, is yet to arrive in Ankara.
Der Spiegel said that in 2006 the NSA began a major surveillance operation aimed at hacking into the computers of Turkey's leadership.
The aim was to glean information about the intentions of the leadership under Recep Tayyip Erdogan, who on Thursday was inaugurated as president after over a decade as prime minister.
It said that the US also spied on Turkey's embassy in Washington and its mission at the UN.
According to Der Spiegel, the NSA placed Turkey "ahead of Cuba, in terms of US interest in intelligence collection".