DAVOS, Switzerland >> The top diplomats of Iran and the United States sit down for public — and separate — one-on-one chats while the U.N. chief and leaders of France, Argentina and Spain will deliver speeches as the World Economic Forum’s annual meeting saunters into a busy second day on Wednesday.

The elite gathering in the Swiss ski resort of Davos takes a turn toward the environmental and climate concerns that have animated plea after plea from U.N. Secretary-General Antonio Guterres for the world to come together do take more united action against global warming — after a record-hot year in 2023.

Experts and policymakers will take up issues like ensuring a sustainable Middle East and North Africa, working to crack down on plastic waste and searching for ways to maintain life on Earth, no less, amid growing threats to biodiversity.

U.S. Secretary of State Antony Blinken, after a day of meetings Monday including one with Ukrainian President Volodymyr Zelenskyy, is on tap for a broadcast conversation with New York Times columnist Tom Friedman. Iranian Foreign Minister Hossein Amirabdollahian will speak with CNN’s Fareed Zakaria.

On Tuesday, U.S. forces led a new strike against Iran-backed rebels in Yemen, known as Houthis, who have been troubling Red Sea shipping lanes in recent weeks by firing missiles against vessels off the coast of the impoverished and divided Arabic Peninsula country. It came hours after one missile strike earlier Tuesday hit a U.S. vessel.

The Yemeni rebels have carried out the campaign in response to Israel’s war against Hamas in Gaza since Oct. 7, when the Palestinian militant group carried out a murderous rampage in Israel and seized hostages.

French President Emmanuel Macron, recently reappointed Spanish Prime Minister Pedro Sanchez and Argentina’s new president — self-described “anarcho-capitalist” Javier Milei — will take the podium Wednesday afternoon, after a morning address by Guterres.

On Tuesday, Zelenskyy shuttled from room to room to meet with CEOs, financiers and political leaders and made a speech blasting his Russian counterpart, Vladimir Putin, over Moscow’s long-running military campaign in Ukraine and seeking more Western support when Ukraine’s allies are showing signs of war fatigue.

“Please, strengthen our economy, and we will strengthen your security,” the Ukrainian leader said.