Trump has called global warming a hoax and has promised to quit the 2015 Paris climate agreement.
Kitack Lim, secretary-general of the International Maritime Organization (IMO), said in an interview last week: "I believe the main policy of the Paris agreement will be maintained ... I am rather optimistic."
U.N. Secretary-General Ban Ki-moon says that action on climate change has become unstoppable.
Ban, at a meeting of 200 nations in Morocco to work out ways to implement the Paris agreement, expressed hopes that U.S. president-elect Trump would drop plans to quit a global accord aimed at weaning the world off fossil fuels.
The shipping industry, like aviation, was excluded from any target cuts under the Paris deal, which set a goal of restricting the rise in global average temperature to less than 2 degrees Celsius.
But last month, the U.N.'s aviation agency ICAO approved an accord to curb aviation pollution which will set voluntary targets from 2021 to 2026 and become mandatory from 2027 for states with larger aviation industries.
