<prompt> Translate the following text to EnglishMnamo mwaka wa 1984, Waziri Mkuu Margaret Thatcher alisaini Azimio la Pamoja la China na Uingereza, ambalo lilithibitisha uhamisho wa Wilaya Mpya na Hong Kong nzima kwa China mnamo 1997.  <response>: Negotiations began, and in 1984 Prime Minister Margaret Thatcher signed the Sino-British Joint Declaration, in which Britain confirmed the transfer of the New Territories and all of Hong Kong to China in 1997. 