Wrapping up the Shaping the Future of Shipping conference, International Maritime Organization secretary general Kitack Lim said he felt the pressure for the UN body to upgrade its ambitions for shipping to decarbonise.
His comments at the conference hosted by the International Chamber of Shipping came as COP26 negotiations geared up for transport discussions on Wednesday.
"We must upgrade our ambition, keeping up with the latest developments in the global community," Lim said.
"The calls for action by world leaders, both from government and business, are loud and clear in the past week at COP26. We need to act now, we need to act urgently but we also need to act collectively, inclusively, equitably and sustainably, leaving no one behind."
He added that he is certain that the momentum from COP26 will be a driving force for progress at the IMO.
Discussions about the scope of the IMO's target for decarbonisation are on the agenda for the 77th Marine Environment Protection Committee (MEPC77) meeting, which takes place this month after the COP negotiations wind up.
Shipping organisations have lined up to urge approval at MEPC77 of an ICS proposal to set up the International Maritime Research Board (IMRB), a research and development structure to develop alternative fuels.
Lim referred to the urgency to facilitate the R&D effort in his speech, as well as incentivising early movers that adopt greener fuels.
He also stressed the importance of ensuring the difficulties experienced by developing countries in adopting climate change policies are addressed, and that they receive the help they need.
There is a firm understanding among IMO member states that policies to address climate change cannot be avoided or escaped, Lim added.
In his closing comments, ICS vice chair for Norway Lasse Kristoffersen said: "Rhetoric has come a long way, but actions have just started."
The shipping industry must do everything it can now in the short term to make vessels more carbon effective while working for the long term and not waiting for the big solution, he added.
He summarised a three-point plan to rapidly scale and deploy technologies for zero emissions
"I have not heard a better idea today than the fund [IMRB] that is proposed to the IMO," he said.
Kristoffersen added that market-based measures are also needed and everything must be done in a just way.
"If this is something we can bring to the transport day next week, I think we can make some progress," he said.