German Foreign Minister Heiko Maas says a treaty on disarmament and nuclear nonproliferation is in crisis.

Maas, who is attending a one-day meeting on the subject Tuesday in Stockholm, after a trip to Iran for talks on the country's nuclear program, says it is important that so many nations are coming together to work on strengthening and preserving the nuclear nonproliferation treaty.

"The treaty is in an acute crisis," he said in a statement. "The nations with atomic weapons need to shoulder their responsibilities for disarmament better and at the same time we need to prevent further countries from obtaining nuclear weapons."

Sweden wants to discuss how governments can work together to create political pressure for disarmament and engagement ahead of next year's conference on the treaty.