Since the discovery of petroleum in the Timor Sea in the 1970s, there have been disputes surrounding the rights to ownership and exploitation of the resources situated in a part of the Timor Sea known as the Timor Gap, which is the area of the Timor Sea which lies outside the territorial boundaries of the nations to the north and south of the Timor Sea. These disagreements initially involved Australia and Indonesia, although a resolution was eventually reached in the form of the Timor Gap Treaty. After the declaration of East Timor's nationhood in 1999, the terms of the Timor Gap Treaty were abandoned and negotiations commenced between Australia and East Timor, culminating in the Timor Sea Treaty.