(Reuters) -British officials held private talks with their U.S. counterparts to resolve concerns that UK is trying to force Apple ( AAPL ) to build a backdoor into Americans' encrypted data, Bloomberg News reported on Thursday, citing people familiar with the matter.

The report about private discussions comes after Apple ( AAPL ) removed its most-advanced security encryption for cloud data, known as Advanced Data Protection, in Britain last month.

The move was an unprecedented response to government demands for user data access.

The removal of encryption gives the iPhone maker access to iCloud backups in certain cases that it otherwise could not, such as copies of iMessages, and hand it over to authorities if legally compelled.

With end-to-end encryption enabled, even Apple ( AAPL ) could not access the data.

Apple ( AAPL ) and Britain's Home Office did not immediately respond to a Reuters request for comment.

Governments and tech giants have long been locked in a battle over strong encryption to protect consumers' communications, which the authorities view as an obstacle to mass surveillance and crime fighting programs. But Britain's demands are considered particularly extensive.

Reuters reported in late February that U.S. officials were examining whether the U.K. broke agreements between the two nations with a reported demand that Apple ( AAPL ) create a "back door" for government access to encrypted cloud storage systems.

In a letter dated February 25 to two U.S. lawmakers, Tulsi Gabbard, the U.S. director of national intelligence, said the U.S. is investigating whether the UK government had violated the CLOUD Act, which bars it from issuing demands for the data of U.S. citizens and vice versa.

Gabbard's office could not immediately be reached for a comment.

On Friday, Apple's ( AAPL ) appeal against the UK order will be heard at a secret hearing at London's High Court, the BBC reported.

(Reporting by Bhanvi Satija and Zaheer Kachwala in Bengaluru; Editing by Arun Koyyur and Tasim Zahid)