BRUSSELS — Scrambling to save the nuclear agreement with Iran, European foreign ministers declared Monday that Iranian breaches so far were not serious enough to take steps that could lead to reimposed international sanctions and a collapse of the accord.

That conclusion, reached at a meeting in Brussels, effectively extended a lifeline for the 2015 nuclear agreement in defiance of pressure by the Trump administration. The agreement has been increasingly imperiled since the United States abandoned the accord more than a year ago and renewed its own sanctions on Iran.

The European Union ministers reiterated their view that the agreement was the only option for curbing Iran’s nuclear program.

In recent weeks Iran has exceeded the amount and purity of the uranium it is permitted under the accord, transgressions confirmed by the International Atomic Energy Agency. The Iranians have said they intend to breach the limits even more unless they get what the accord promised Iran: economic relief.