Britain quickly re-established this unofficial part of the agreement and attacked Kowloon Walled City in 1899 to find it abandoned. They didn`t do anything with it, or the outpost, and the question of ownership of Kowloon Walled City was directly in the air. The outpost consisted of a yamen, as well as buildings that grew up in sparsely populated neighborhoods from the 1890s to the 1940s. First, the declaration itself does not have a mechanism approved by both parties to ensure compliance. Although the agreement was registered with the United Nations, it did not contain any UN monitoring mechanisms, unlike the Finnish islands. Therefore, only the signatories of the declaration have the right to address any violations of the conditions. This is what happened in 1992, when Hong Kong Governor Chris Patten proposed political reforms without prior consultation with China, which responded by accusing Britain of violating the declaration. In theory, China could have filed a formal complaint against Britain, but it renounced it, perhaps in the hope of a smooth transfer process. Similarly, after the recent events, Britain criticized China for violating the agreement, but this would have no concrete impact if the case were not formally brought before an international tribunal, according to the International Court of Justice (ICJ), for infringement. On 19 December 1984, after years of negotiations, the British and Chinese leaders signed a formal pact authorizing the colony`s turnover in 1997, in exchange for formulating a Chinese Communist government policy with a “one country, two systems”.
Prime Minister Margaret Thatcher called the agreement “a milestone in the life of the territory, in anglo-Chinese relations and in the history of international diplomacy.” Hu Yaobang, the general secretary of the Communist Party of China, called the signing “a day of red letters, an occasion of great joy” for one billion people in China. The signing of the joint declaration caused some controversy in the United Kingdom, as British Prime Minister Margaret Thatcher accepted the Chinese Communist government, represented by Deng Xiaoping.  In the White Paper containing the Joint Statement, Her Majesty`s Government stated that “the alternative to the adoption of this agreement is not to reach an agreement”, a statement that refuted criticism that the Declaration had made too many concessions to China and highlighted China`s considerable influence during the negotiations.  The Communist press published reports that the project was a bad plan to bleed Hong Kong before handover and let the territory take on serious debt.  After three years of negotiations, Britain and the PRC finally agreed on the construction of the new airport and signed a Memorandum of Understanding.  To remove the hills and reclaim the land, it took only a few years to build the new airport.