European Commission President Jean-Claude Juncker (2nd R) meets with Chinese State Councilor and Foreign Minister Wang Yi (2nd L) at the European Commission headquarters in Brussels, Belgium, June 1, 2018. (Xinhua/Ye Pingfan)

BRUSSELS, June 1 (Xinhua) -- The use of unilateral sanctions in international affairs is totally unacceptable, European Commission President Jean-Claude Juncker told top Chinese diplomat on Friday.

Juncker's remarks came in the wake of Washington's decision not to extend the temporary steel and aluminum tariff exemptions for the EU, Canada, and Mexico.

Meeting with Chinese State Councilor and Foreign Minister Wang Yi on the sideline of the eighth China-EU High Level Strategic Dialogue, Juncker highlighted the importance of enhancing EU-China strategic ties, citing the international situation which is undergoing complicated and profound changes.

In this context, safeguarding multilateralism and free trade is not only at stake for the EU and China, but also for the rest of the world, said Juncker.

The EU highly values its cooperation with China, said Juncker, adding that he looks forward to the 20th EU-China summit slated for next month, and believes that the summit will be a complete success due to the concerted efforts of both sides.

Echoing Juncker, Wang said the current international situation is plagued by uncertainties, as well as rising unilateralism and protectionism.

As two major forces in the world, China and the EU should jointly safeguard the purposes and principles of the UN Charter, improve global governance, and advocate an open world economy, Wang added.

China stands ready to join hands with the EU to reach important consensus and achieve practical results at the upcoming summit, thus sending out a positive signal, said Wang.

In a statement on Thursday, Juncker lambasted U.S. tariffs on EU steel and aluminum, stressing that they are "unjustified and at odds with World Trade Organization rules".

"This is protectionism, pure and simple," said Juncker.