Brussels, Belgium – US President Joe Biden is to take part in his debut NATO summit on Monday as the 30 countries look to put the strained years of Donald Trump's administration behind them and instead turn their attention to external threats.

Leaders are expected to send a pointed message to an increasingly aggressive Russia – the defense alliance's traditional adversary – and to address China's ascendancy on the world stage, security issues linked to climate change, cyber defense, and new military technology.

In addition, the allies should sign off a reform plan for 2030 and formally decide to start overhauling their core strategic concept, which was last updated in 2010.

The US leader is also planning a bilateral meeting with Turkish President Recep Tayyip Erdoğan.

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Another important issue is NATO's ongoing withdrawal from Afghanistan, almost 20 years after the US invasion in the wake of the 9/11 attacks.

While the NATO allies are to keep up funding as well as security and civilian support, the exact nature of future cooperation with Afghan authorities is yet to be determined.

The drawdown, set to be completed later this year, is coinciding with increased bloodshed in Afghanistan, with the militant Islamist Taliban group regaining control over territory.

According to a White House statement, Biden will "reaffirm the enduring transatlantic bond through NATO and underscore the US ironclad commitment to Article 5 – an attack on one is an attack on all and will be met with a collective response."

Frustrated by what Washington has long viewed as unfair defense spending imbalances among the allies, former US president Trump repeatedly raised doubts whether his country would provide military assistance in a crisis. He even threatened to leave NATO.

Though more conciliatory in tone, the Biden administration still wants to see other allies spend more on defense.

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NATO chief Jens Stoltenberg said Friday he expected allies to agree on funding commitments reflecting their heightened ambition, but made no mention of his original, bolder proposal to jointly fund exercises in the bloc's eastern flank.

This had been a key element of the 2030 modernization drive, but according to multiple sources within the alliance, has been scaled back in negotiations in the run-up to the summit.

A handful of the leaders come fresh from the Group of Seven (G7) summit of major industrialized nations in Cornwall, England, where they committed to take a tougher stance on Beijing on matters such as unfair trade practices, human rights issues, and the crackdown on the opposition in Hong Kong.

At the same time, the G7 declaration underlined a common interest in cooperation with China on global challenges like climate change.

NATO leaders are expected to strike a similar tone, highlighting potential security challenges but also opportunities to work together.