Taoiseach Micheál Martin has described as "disappointing" the absence of a high-ranking delegation from the United States at a United Nations Ocean Conference (UNOC3) in Nice, France.
He told RTÉ News that Ireland is "committed to multilateralism" and believes in countries coming together to solve the problems of the world.
"The United Nations is the key framework for resolving global problems, developing mutual cooperation between states and ensuring some governance and ensuring some governance," he said.
In April, US President Donald Trump issued a new executive order to open up parts of the Pacific Ocean for commercial fishing.
That same month, Mr Trump's administration fast-tracked the permit process for deep-sea mining in US and international waters.
Such policies are at odds with the goals of UNOC3, which aims to deliver an urgent action plan to conserve and sustainably use the world's oceans.
This morning, a number of world leaders called on more countries to ratify the High Seas Treaty, which was adopted in 2023 and is an agreement on protecting marine species in international waters.
Fifty countries have now signed and ratified the treaty, short of the required number of 60 countries for the treaty to come into force under international law.
The United States has not ratified the treaty and will not do so during this conference, said the Director of the High Seas Alliance, Rebecca Hubbard.
Ireland signed the treaty in 2023 and the Taoiseach indicated that Ireland plans to ratify it but did not confirm whether that ratification would take place this week at the conference.
"We will seek to discuss it with the relevant ministers that we may ratify this treaty in advance of the transposition of an expected EU directive on it, but certainly we will ratify it," he said.
"We're very committed to it."
In a speech to delegates at the conference, Mr Martin said that the protection of Ireland's "marine environment and its biodiversity is paramount" and remains a "central part of creating future plans for our marine space in Ireland".
Mr Martin said that it was imperative that delegates use the conference "to learn from each other and work together for a better future for our oceans".
"Climate finance is an integral part of Ireland’s foreign policy," said Mr Martin, adding that the Government would spend at least €225 million this year on climate finance, as outlined in last year's budget.
"Our aim is to use our voice to advocate for the countries most at risk from the effects of climate change," he said.
Mr Martin also reiterated Ireland’s existing marine policy, first announced by the previous coalition government in 2023, to designate 30% of Ireland’s sea area as "protected" by 2030.
Speaking at the opening of the conference earlier, UN Secretary-General António Guterres urged world leaders to ratify the treaty.
He cautioned that illegal fishing, plastic pollution and rising sea temperatures threatened delicate ecosystems and the people who depend on them.
"The ocean is the ultimate shared resource. But we are failing it," Mr Guterres said, citing collapsing fish stocks, rising sea levels and ocean acidification.
Oceans also provide a vital buffer against climate change, by absorbing around 30% of planet-heating CO2 emissions. But as the oceans heat up, hotter waters are destroying marine ecosystems and threatening the oceans' ability to absorb CO2.
"These are symptoms of a system in crisis - and they are feeding off each other. Unravelling food chains. Destroying livelihoods. Deepening insecurity."
The treaty would permit countries to establish marine parks in international waters, which cover nearly two-thirds of the ocean and are largely unregulated.
Hitherto, only an estimated 1% of international waters, known as the "high seas", have been protected.
The drive for nations to turn years of promises into meaningful protection for the oceans comes as President Trump pulls the United States and its money out of climate projects and as some European governments weaken green policy commitments as they seek to support anaemic economies and fend off nationalists.
French President Emmanuel Macron, the conference's co-host, told delegates that 50 countries had now ratified the treaty and that another 15 had promised to do so.
He also said it was "not a surprise" that the US did not send a high-level delegation to the conference.
"We know the American administration's position on these issues," Mr Macron said.
Britain's Prince William said protecting the planet's oceans was a challenge "like none we have faced before".
Ocean experts have also seized on the conference as an opportunity to rally investment for the ocean economy, which has long struggled to attract sizeable funding commitments.
At a two-day gathering of bankers and investors in Monaco over the weekend, philanthropists, private investors and public banks committed €8.7 billion over five years to support a regenerative and sustainable blue economy.
Investments in ocean health totalled just $10bn from 2015-2019 - far below the $175bn per year needed, the UN has said.
To address this gap, the UN said it was starting work to design a new financing facility, to be launched in 2028, which aims to unlock billions of dollars to restore ocean health by mobilising new and diverse sources of capital.
Additional reporting by Reuters
