European countries warned Friday against an escalating conflict in the Middle East after the killing of an Iranian top commander in a U.S. airstrike in Iraq.

“We have always recognized the aggressive threat posed by the Iranian Quds force led by Qasem Soleimani. Following his death, we urge all parties to de-escalate. Further conflict is in none of our interests,” U.K. Foreign Secretary Dominic Raab said on Twitter.

German government spokesman Ulrike Demmer voiced his concern and said regional problems can be only solved diplomatically and Germany is in contact with allied countries.

President of the European Council Charles Micheal said further escalation must be stopped.

“The cycle of violence, provocations and retaliations which we have witnessed In Iraq over the past few weeks has to stop. Further escalation must be avoided at all cost,” he said.

“The risk is a generalized flare up of violence in the whole region and the rise of obscure forces of terrorism that thrive at times of religious and nationalist tensions,” he added.

NATO spokesperson Dylan White told Anadolu Agency that “NATO is monitoring the situation in the region very closely. We remain in close and regular contact with the US authorities.”

“The safety of our personnel in Iraq is paramount. We continue to monitor the security environment and take all precautions necessary,” he said.

The U.S. confirmed Thursday that it carried out a strike that killed Soleimani, commander of the Iranian Revolutionary Guards Corps’ Quds Force.

The Pentagon accused Soleimani of planning to carry out attacks on U.S. diplomats and service members in Iraq and the region, saying he was responsible for the deaths of hundreds of American and coalition service members.

The attack came amid heightened Iranian tensions with the U.S. which culminated Tuesday with the storming of the U.S. Embassy compound by Iraqis.

Read more: European countries warn against Mideast escalation