London, UK - Countries including the UK, United States, and China on Wednesday agreed on the "need for international action" as political and tech leaders gathered for the world's first summit on artificial intelligence (AI) safety.

The UK government kicked off the two-day event at Bletchley Park, north of London, by publishing the "Bletchley Declaration" signed by 28 countries and the European Union.

In it, they agreed on "the urgent need to understand and collectively manage potential risks through a new joint global effort to ensure AI is developed and deployed in a safe, responsible way for the benefit of the global community."

Sunak called the declaration a "landmark achievement," while King Charles III, in a video message to the summit, urged international collaboration to combat the "significant risks" of unchecked development.

"There is a clear imperative to ensure that this rapidly evolving technology remains safe and secure," he said.

UK technology minister Michelle Donelan told AFP that the declaration "really outlines for the first time the world coming together to identify this problem."

The announcement came shortly after the UK and US both said they were setting up their own institutes to assess and mitigate the risks of the fast-emerging technology.

The release of the latest models has offered a glimpse into the potential of so-called frontier AI but has also prompted concerns around issues ranging from job losses to cyber attacks and the control that humans actually have over the systems.

The conference at Bletchley Park, where top British codebreakers cracked Nazi Germany's "Enigma" code, focuses on frontier AI.

Donelan told AFP the event was a "historic moment in mankind's history" after earlier announcing two further summits, in South Korea in six months' time and in France next year, but London has reportedly had to scale back its ambitions around ideas such as launching a new regulatory body amid a perceived lack of enthusiasm.

Donelan accepted that the summit "isn't designed to produce a blueprint for global legislation" but was instead "designed to forge a path ahead... so that we can get a better handle and understanding on the risk of frontier AI".

Italian Prime Minister Giorgia Meloni was one of the only world leaders attending the conference, although tech giant Elon Musk was already present on the first day and will talk with Sunak on Thursday.

The SpaceX and Tesla CEO told the domestic Press Association news agency that the event was "timely."

"It's one of the existential risks that we face, and it is potentially the most pressing one if you look at the timescale and rate of advancement - the summit is timely, and I applaud the prime minister for holding it," he said.

While the potential of AI raises many hopes, particularly for medicine, its development is seen as largely unchecked.

Vice President Kamala Harris urged in a speech in London on Wednesday that "we seize this moment" and "work together to build a future where AI creates opportunity and advances equity" while protecting rights.

Ahead of the meeting, the G7 powers agreed on Monday on a non-binding "code of conduct" for companies developing the most advanced AI systems.

In Rome, ministers from Italy, Germany, and France called for an "innovation-friendly approach" to regulating AI in Europe, as they urged more investment to challenge the United States and China.

China was also due to be present, but it was unclear at what level. News website Politico reported that London had invited President Xi Jinping to signify its eagerness for a senior representative.