Scott Morrison and Prime Minister of Timor-Leste Taur Matan Ruak upon the ratification of the maritime boundary treaty (Image: AAP/Lukas Coch)

Hundreds of children are sitting in the heat of the Dili sun; their crisp white t-shirts read "Viva, Timor-Leste" in soda-brand font. Each child clutches two small flags mounted on thin plastic poles -- one Australia’s, one Timor-Leste’s.

They’re waiting in the grassy grounds of Palàcio do Governo, Timor-Leste’s government house, ahead of Scott Morrison’s arrival. The upcoming ceremony will officially mark the long-awaited ratification of the maritime boundary between Australia and Timor-Leste -- the troka nota, or "exchange of letters".