Colin Tukuitonga was speaking as the regional agency marked its year of operations.
The US is a founding member and a significant funder of programmes undertaken by the SPC, which include extensive climate change activities.
But the Trump administration is full of climate change deniers and the president has said it is a hoax perpetrated by China.
Dr Tukuitonga said the SPC had worked constructively with the US in the past and their new direction was a concern.
But he said there was momentum on climate change and the SPC was hoping the global community would continue to support the agreements that had already been signed.
And certainly from our point of view we look forward to continuing the work and recognising the change in priorities. But we are confident that there is sufficient momentum, there is sufficient concern, and that we push ahead and honour those commitments that have been made by the global community.
Photo: Pacificwomen.org SPC Director-General, Colin Tukuitonga.