Sydney and Auckland have become the world’s first major cities to ring in 2024, with huge crowds of revellers cheering spectacular firework displays that lit up the skies over Sydney Harbour and New Zealand’s tallest structure, Sky Tower.

As the clock struck midnight in Australia’s largest city, tons of explosives erupted in a 12-minute display that focused on the Sydney Harbour Bridge.

More than a million people – equivalent to one in five of the city’s residents – watched from the shore and from boats.

“It’s total madness,” said German tourist Janna Thomas, who had queued since 7.30am to secure a prime waterfront location in the Sydney Botanic Garden. “It’s not so easy to find a good place to sit, but the view is incredible.”

In Auckland, the light rain that fell all day had cleared as forecast by midnight over the city of 1.7 million people before the countdown began on an illuminated digital display near the top of the 1,076ft (328m) communications and observation tower.

The ongoing wars in Ukraine and Gaza, and heightened tensions in parts of the world, are affecting this year’s New Year’s Eve celebrations in a myriad of ways. Many cities were deploying extra security, and some places cancelled New Year’s Eve events altogether.

More police than ever were deployed throughout Sydney.

The waterfront has been the scene of heated pro-Palestinian protests after the sails of the Sydney Opera House were illuminated in the colours of the Israeli flag in response to the October 7 attack by Palestinian militant group Hamas that triggered the war.

At the Vatican, Pope Francis recalled 2023 as a year marked by wartime suffering.

During his traditional Sunday blessing from a window overlooking St Peter’s Square, he offered prayers for “the tormented Ukrainian people and the Palestinian and Israeli populations, the Sudanese people and many others”.

“At the end of the year, we will have the courage to ask ourselves how many human lives have been shattered by armed conflict, how many dead and how much destruction, how much suffering, how much poverty,” he said.

“Whoever has interest in these conflicts, listen to the voice of conscience.”

In Japan, temple bells rang out across the nation as people gathered at shrines and temples to welcome in the new year.

At the Tsukiji Temple in Tokyo, visitors were given free hot milk and corn soup as they queued to strike a big bell, and a pipe-organ concert was held before a majestic altar.

In New York’s Times Square, officials and party organisers said they are prepared to welcome crowds of revellers and ensure their safety.

At a security briefing on Friday, New York City Mayor Eric Adams said there are “no specific threats” to the annual New Year’s Eve bash, which is expected to draw tens of thousands of people to the heart of midtown Manhattan.

The celebrity-filled event will include live performances from Flo Rida, Megan Thee Stallion and LL Cool J, as well as televised appearances from Cardi B and others.

Organisers said in-person attendance is expected to return to pre-Covid levels, even as foot traffic around Times Square remains down slightly since the pandemic.

Amid near-daily protests in New York sparked by the Israel-Hamas war in the Gaza Strip, police said they would expand the security perimeter around the party, creating a “buffer zone” which will allow them to head off potential demonstrations.

“We will be out here with our canines, on horseback, our helicopters, our boats,” Mr Adams said.

Officials will also monitor protests with drones, he added. “But as we saw last year, after having no specific threats, we get a threat.”

During last year’s New Year’s Eve party, a machete-wielding man attacked three police officers a few blocks from Times Square.

Security will also be heightened across France on Sunday, with 90,000 law enforcement officers set to be deployed, domestic intelligence chief Celine Berthon said on Friday.

Of those, 6,000 will be in Paris, where French Interior Minister Gerald Darmanin said more than 1.5 million people are expected to attend celebrations on the Champs-Elysees.

Speaking at a news conference, Mr Darmanin cited a “very high terrorist threat” because, in part, of “what is happening in Israel and Palestine”..

The minister said that police for the first time will be able to use drones as part of security work and that tens of thousands of firefighters and 5,000 soldiers will also be deployed.

New Year’s Eve celebrations in the French capital will centre on the 2024 Paris Olympic Games, including DJ sets, fireworks and video projections on the Arc de Triomphe, highlighting “changes in the city and faces of the Games”, according to the press service of the City of Paris.

Other planned events include “the largest Mexican wave ever performed” and a “giant karaoke”.

Local authorities have instituted a ban on the sale of alcohol on and around the Champs Elysees on New Year’s Eve, and the public will not be able to access the area with glass bottles and flasks.

In Russia, the country’s military actions in Ukraine have overshadowed end-of-year celebrations, with the usual fireworks and concert on Moscow’s Red Square cancelled, as last year.

After shelling in the centre of the Russian border city of Belgorod on Saturday killed 24 people, some local authorities across Russia also cancelled their usual firework displays, including in Vladivostok.

Millions throughout Russia are expected to tune into Russian President Vladimir Putin’s New Year’s address.

In Muslim-majority Pakistan, the government has banned all New Year’s Eve celebrations as an act of solidarity with the Palestinians.

In an overnight televised message, caretaker Prime Minister Anwaar-ul-Haq Kakar urged Pakistanis to “show solidarity with the oppressed people of Gaza” by beginning the new year with simplicity.

He said Muslims across the world are saddened over Israel’s attacks on Gaza which have resulted in the killings of thousands of innocent people.