The foreign ministers of the BRICS emerging economies have criticized what they call a "new wave of protectionism," a reference to U.S. President Donald Trump's tough trade negotiations with key economic partners.

The envoys from Brazil, Russia, India, China and South Africa referred to "unilateral measures that are incompatible with" international trade rules after a meeting Monday in the South African administrative capital of Pretoria.

The foreign ministers say Trump's measures undermine global trade and economic growth.

Trump has imposed tariffs on steel and aluminum imports from top U.S. trading partners, including Canada, Mexico and the European Union. He has threatened tariffs on up to $200 billion in Chinese imports, raising the potential for retaliation.

Trump also says U.S. farmers have been treated "unfairly" and says "that will change."