The leaders of the 28 members of the European Union are showing their support for the Iran nuclear agreement, despite U.S. President Donald Trump’s opposition to it.

EU spokesman Preben Aaman tweeted that the EU leaders agreed at a summit Thursday to show their joint commitment to the international agreement curbing Iran’s nuclear program.

The EU leaders called the 2015 deal a pillar of efforts to reduce the global nuclear threat. Some fear that walking away from the deal could compromise chances of encouraging North Korea to negotiate on its nuclear program.

Trump “decertified” the deal Friday, angrily accusing Iran of violating it, and directed the U.S. Congress to make it more stringent.

The International Atomic Energy Agency has certified eight times that Iran was living up to its commitments.