Brazil criticized the "paralysis" of the UN Security Council on the wars in Gaza and Ukraine as it opened a G20 meeting Wednesday where the international community's deep divisions were on display.

The outlook is bleak for progress on the thorny agenda of conflicts and crises gripping the planet as foreign ministers from the world's biggest economies gather in Rio de Janeiro for the Group of 20's first high-level meeting of the year.

Opening the two-day meeting, which featured US Secretary of State Antony Blinken and Russian Foreign Minister Sergei Lavrov, Brazil's top diplomat, Mauro Vieira, said the explosion of global conflicts shows international institutions like the United Nations are not working.

"Multilateral institutions are not properly equipped to deal with the current challenges, as has been demonstrated by the Security Council's unacceptable paralysis on the ongoing conflicts" in Gaza and Ukraine, Vieira said, adding the situation was costing "innocent lives."

EU foreign policy chief Josep Borrell for his part warned multilateralism "is in crisis."

The Security Council has failed to act on Russia's invasion of Ukraine, held in check by Russian veto power, and has struggled to find a response to the war in Gaza, with Israel's ally the United States using its veto to block calls for a ceasefire, most recently Tuesday.

Brazil, which took over the rotating G20 presidency from India in December, has voiced hopes the group could be a forum to make progress on such questions.

But that likely took a hit when Lula ignited a diplomatic firestorm Sunday by accusing Israel of "genocide," comparing its military campaign in the Gaza Strip to the Holocaust.

The comments drew outrage in Israel, which declared him persona non grata, and could overshadow any bid to de-escalate the conflict via the G20.

Blinken, who met Lula Wednesday in Brasilia before heading to the G20, "made clear we disagree with (his) comments," a senior State Department official told journalists.

The secretary of state and Brazilian leader had a "frank exchange" in their more than 90-minute meeting at the presidential palace, the official said.

- Wars of words -

More than four months after the Gaza war started with Hamas fighters' unprecedented October 7 attack on Israel, which has vowed to wipe out the Islamist group in retaliation, there is little sign of progress toward peace.

The outlook is similarly grim on Russia's war in Ukraine, which also has G20 members divided as the second anniversary of President Vladimir Putin's invasion approaches.

Despite a push by Western countries to condemn the invasion, the G20's last summit ended with a watered-down statement denouncing the use of force but not explicitly naming Russia, which maintains friendly ties with India and Brazil, among other members.

UK Foreign Secretary David Cameron said he planned to use the Rio meeting to "call out Russia's aggression" directly to Lavrov, as Britain announced sanctions on six Russian officials over opposition leader Alexei Navalny's death in prison last week.

Lavrov -- who will meet Lula in Brasilia Thursday, according to a Brazilian official -- meanwhile lashed out at the West for "pumping Ukraine full of arms."

"Neither Kiev nor the West have shown the political will to resolve the conflict," he told Brazilian newspaper O Globo.

Blinken voiced pessimism on the current chances for diplomacy on Ukraine in his meeting with Lula. "We don’t see the conditions for it right now," a US official said.

- Blinken-Lavrov -

Brazil also wants to use its G20 presidency to push the fights against poverty and climate change.

There will also be space for bilateral meetings on the sidelines of the gathering -- though a Blinken-Lavrov encounter looks unlikely, given soaring tensions.

The pair last met in person at a G20 gathering in India in March 2023.

Founded in 1999, the G20 brings together most of the world's biggest economies.

Originally an economic forum, it has grown increasingly involved in international politics.

A Brazilian government source said that after recent G20 struggles for consensus, the hosts axed the requirement that every meeting produce a joint statement -- with the exception of the annual leaders' summit, scheduled for November in Rio.

© Agence France-Presse