dpa

Washington

US President Joe Biden was meeting his fellow NATO leaders on Tuesday for a landmark 75th-anniversary summit aimed at projecting strength and shoring up support for Ukraine in its defence against the Russian invasion.

However, questions surrounding Biden’s mental fitness for office loom over the summit, as the US presidential race heats up between the president and his predecessor, longtime NATO critic Donald Trump.

Founded in Washington in 1949 by the United States and 11 other countries at the onset of the Cold War to deter the expansion of the communist Soviet Union, NATO has grown to 32 members with Sweden and Finland’s recent entry.

The alliance is a collective security pact in which, according to Article 5 of the NATO founding treaty, an attack on one member "shall be considered an attack against them all.” Article 5 has been only invoked once, after the terrorist attacks of September 11, 2001, killed nearly 3,000 people in the US.

Despite the importance of NATO to US foreign relations, Trump has openly cast doubt on US collective defence commitments during his term of office and threatened to withdraw over defence spending rows.

Trump has railed against European allies that do not meet NATO’s defence spending target of 2 percent of national gross domestic product (GDP).

Several NATO allies have increased their defence budgets since the full-scale Russian invasion of Ukraine in 2022.

Last month, outgoing NATO Secretary General Jens Stoltenberg announced on a visit to Washington that 23 NATO allies will spend 2 percent of GDP on defence, up from 18 members.

Biden has resisted calls to withdraw from the presidential race and may use the summit to dispel doubts over his health, while NATO tries to entrench its support for Ukraine in the event Trump returns to the White House.

Stoltenberg announced the alliance is set to provide Ukraine with military aid worth €40bn ($43bn) in 2025 in a press conference ahead of the summit. But the €40bn pledge has been watered down from the multi-year financial commitment for Ukraine that Stoltenberg wanted allies to agree.