MOSCOW (Sputnik) - The European Union regrets US decision to impose sanctions against Iranian Foreign Minister Mohammad Javad Zarif and intends to keep working with him, Carlos Martin Ruiz de Gordejuela, the spokesman of the European Commission for the international cooperation and development, said Thursday.

"We regret this decision, and from our side, we will continue to work with Mr Zarif as Iran's most senior diplomat, and in view of the importance of maintaining diplomatic channels", the spokesman told reporters.

At the same time, Chinese Foreign Ministry spokeswoman Hua Chunying also slammed Washington's decision.

"We have taken note of the statement of the US side and the reaction of Mr. Zarif himself. The position of the Chinese side on this issue is very clear. China opposes unilateral US actions ... We think it is not facilitating the solution of the problem", Hua said at a briefing.

She stressed that negotiation and dialogue were the best ways to solve the problem.

"The US has repeatedly stated that it is ready to hold talks with Iran without preconditions. We hope that the actions of the United States will not diverge from their statements", the spokeswoman noted.

The US Department of the Treasury announced earlier this week that Washington had imposed sanctions on Zarif. At the same time, Treasury Secretary Steven Mnuchin claimed that the United States would not recognise Zarif's role in potential negotiations of a new nuclear agreement with Tehran.

Iranian President Hassan Rouhani called the sanctions "childish behaviour" and said that Washington had "lost the power of rational thought".

Tensions between the US and Iran escalated after Washington unilaterally pulled out of the 2015 nuclear deal with the Islamic Republic in May 2018 and reinstated all sanctions against the country, stating they would bring Iranian oil exports to zero.

Precisely one year after the US move, Tehran stated it would partially suspend obligations under the agreement. At the same time, US increased number of troops in the region, which ensionsin the Middle East.