The COP30 climate conference in the Amazonian city of Belem marks a decade since the signing of the Paris Agreement but follows the second US withdrawal from the landmark pact and global efforts to address climate change and other shared threats.

Andre Correa do Lago, a veteran climate diplomat tapped to lead the November COP30 conference, acknowledged that the world faces "immense" challenges, with geopolitical tensions and data showing global temperatures at historic highs.

In his second letter to the nearly 200 nations set to take part in COP30, Correa do Lago called on the international community to "mobilize in the face of climate urgency".

And he insisted that the meeting can serve "as an inflection point in our historic transition that closed the gaps and charted the course toward a new era of sustainable and inclusive prosperity".

- World climate commitments -

Several major economies are still working to finalise their climate plans, known as nationally determined contributions (NDCs), which were originally due earlier this year but are now expected to be submitted to the UN before the COP30 conference.

These commitments must be revised every five years, but few countries have submitted their 2035 plans on time, with major greenhouse gas emitters such as China and the European Union among the latecomers.

"Everybody seems very committed to advance in developing their NDCs and I believe that by September we're going to have a very significant number of countries presenting it," Correa do Lago told reporters.

Speaking on the sidelines of a ministerial meeting in Copenhagen to prepare for the November 10 to 21 COP30 talks, Correa do Lago said the atmosphere was "positive".

Ana Toni, CEO of the COP, said that the quality of countries' climate commitments had changed "tremendously", with more parts of economies included.

With the US withdrawal from climate cooperation under President Donald Trump, attention has turned to other major carbon polluters.

Last month, President Xi Jinping said China would not slow its climate efforts and pledged to announce its 2035 commitments before COP30.

He said that they would for the first time cover the entire economy and all greenhouse gases, not just carbon dioxide.

The European Commission has proposed cutting emissions by 90 percent by 2040 compared to 1990 levels but some member states argue the figure is too high, delaying its approval.

In the letter, Correa do Lago said there was a risk of confronting "new crises with outdated strategies", overlooking shifts in science, technology and societies.

He added that he wanted COP30 to help widen climate action beyond the negotiations and "shift the trajectory of humanity's relationship with the planet".