DAYTON, Ohio (AP) — Representatives from NATO-aligned nations concluded a gathering in Dayton, Ohio, Monday to mark the 30th anniversary of the Dayton Peace Accords, the agreement that ended the Bosnian war, amid Russia’s unprecedented drone offensive in Ukraine.

NATO formed in 1949 to provide collective security against the Soviet Union. It now includes 32 countries. Ukraine is not a member, but participants in NATO gatherings over the past week have said a victory against Russia in the 3-year-old war is crucial to European and global stability.

The anniversary was framed as a celebration of diplomacy and peace. The original accords were negotiated at Wright-Patterson Air Force Base, in Ohio, and signed in Paris later that year.

“The Western Balkans has shown that peace is possible. But today Europe is not at peace. Russia has brought war back to Europe,” said NATO Secretary-General Mark Rutte at Monday’s meeting of the NATO Parliamentary Assembly, the culmination of the five-day gathering.

Rutte called on NATO member leaders to make the case at home for increasing military spending, suggesting that an increase to 5% of gross domestic product over the next few years could be reached in an agreement next month, in line with demands from the NATO member U.S.

Belgium, Canada, Croatia, Italy, Luxembourg, Montenegro, Portugal, Slovenia and Spain do not currently spend at least 2% of GDP on national defense budgets, a goal agreed to in 2023 as Russia’s war on Ukraine entered its second year. So far, 22 of the 32 member countries have done so.

Next month, the members will debate increasing that percentage to 3.5%, plus another 1.5% in spending on defense-related projects like roads and cybersecurity infrastructure.

Cultural events accompanied the official meetings in Ohio, including art and history exhibits, public lectures, and a Concert for Peace featuring musicians from Dayton and Bosnia’s capital of Sarajevo. A downtown “NATO Village” displayed flags from member nations, and additional exhibits highlighted the city’s international ties.