Ukrainian soldiers have battled Russian troops with ammunition that comes mainly from Western allies. Now that the ammunition is running out, the allies have decided to ramp up production to wage what they call a "war of logistics."

NATO defense ministers gathered for two days of meetings in Brussels to address "the biggest security crisis in Europe" since World War Two. They have already delivered a range of weapons, and they are trying to figure out how to pay for more.

Secretary General Jens Stoltenberg said, "This is critical. Ukraine has a window of opportunity to tip the balance, and time is of the essence." He said that, after weeks of warnings, Russian forces are launching a new offensive.

Members have promised more training for Ukrainian troops and more heavy weapons, including Leopard 2 tanks. However, all that support has depleted their stockpiles. They have decided to boost production of 155 millimeter shells to ensure the Ukrainians have "credible deterrence."

NATO members have set a benchmark of spending 2 percent of their gross domestic product on defense. Some of them now say that should be a floor, not a ceiling.

Leaders from Sweden, and Finland, have applied to join the alliance. As they wait, the Swedes have been providing direct military aid to Ukraine, including howitzers and fighting vehicles.

Prime Minister Ulf Kristersson met with Ukrainian President Volodymyr Zelenskyy in Kyiv on Wednesday. He said future aid will depend on Sweden's membership in NATO.