NATO leaders plan to announce arms deals worth tens of billions of dollars in Ankara today, Reuters reported.
The aim is to show that they are listening to U.S. calls for increased European defense spending before joining President Donald Trump at the summit.
European governments will present the deals at a NATO defense industry forum before Trump arrives in Turkey to meet Turkish President Recep Tayyip Erdogan and join other alliance leaders for a meeting that begins with dinner tonight.
NATO Secretary-General Mark Rutte said yesterday that European countries have made "huge" increase in defense spending, partly because of concerns about Russia, which intensified after the Russian invasion of Ukraine in 2022, but also because Trump has been "extremely insistent" in his calls to do so.
Trump has long accused European governments of relying too much on the United States for their defense through NATO, the alliance that has guaranteed the continent's security since the early years of the Cold War.
"We are now creating an alliance that is sustainable, in which the United States knows the deal is fair," Rutte said in Ankara on the eve of the meeting.
Last month, Rutte pointed out that European NATO members and Canada had increased their real defense spending in 2025 by $90 billion compared to 2024, reaching a total of more than $570 billion - an increase of about 20% in just one year.
Can NATO calm Trump's anger?
At the Alliance summit, all eyes will be on the American president
War with Iran renews Trump's criticism of NATO
In recent months, however, Trump has stepped up his sharp criticism of NATO allies, accusing them of not doing enough to help the United States in the war with Iran and hinting that he may leave the alliance or break the mutual defense treaty.
European officials insist that their countries have largely fulfilled their commitments to allow the United States to use their airspace and military bases on their territory, despite not being consulted in advance about the war, which has shaken their economies and was hugely unpopular in Europe.
The United States has also announced the withdrawal of some of its troops from Europe, reduced the forces it provides to NATO's defense plans - including an aircraft carrier, aerial refueling planes, fighter jets and drones - and begun a six-month review of its military presence in continent.
European officials say they are preparing to renew some of Trump's recent criticisms at the summit, but hope Erdogan and Rutte can use their close relationship with the US president to keep the meeting constructive.
However, they acknowledge that they cannot guarantee a positive outcome because of ongoing tensions over Greenland and Iran, as well as Trump's unpredictable dealings with some leaders - most recently demonstrated in his dispute with Italian Prime Minister Giorgia Meloni.
Turkey: US has no intention of leaving NATO
Alliance adapts to new security environment
Secret arms deals
Details of the arms deals to be announced today are being kept secret in an effort by NATO to achieve a strong media effect before the summit.
The minister Dutch Defense Minister Dylan Jeshilgoz said yesterday that his country would announce deals and plans worth more than 3 billion euros ($3.43 billion), including partnerships with Belgium for air defense and with Britain for naval vessels.
NATO also plans to announce that it will replace its aging fleet of U.S.-made AWACS aerial surveillance aircraft with the Swedish company Saab's GlobalEye system.