On 28 May 1975, the Interim Provincial Government in Bougainville agreed to secede from Papua New Guinea. This caused a three-way impasse between the Government of PNG, the legislature in PNG, and the authorities in Bougainville. The PNG government attempted to resolve the situation through June and July, but failed. The Interim Provincial Government announced that they would declare independence on 1 September, ahead of Papua New Guinea's own planned independence day of 16 September. On 1 September, they issued the 'Unilateral Declaration of Independence of the Republic of North Solomons'.