European Council President Donald Tusk attends a news conference after a European Union leaders summit in Brussels, Belgium December 14, 2018. REUTERS/Eric Vidal

BRUSSELS (Reuters) - European Council President Donald Tusk said on Friday he had no mandate to reopen Brexit negotiations with Britain, while the head of the bloc’s executive, Jean-Claude Juncker, said he “admired” Prime Minister Theresa May.

Tusk and Juncker were speaking at a news conference after two days of talks at an EU summit that were dominated by the issue of Brexit and saw the other 27 national leaders of the bloc offer May only vague assurances over their Brexit deal.

“I have no mandate to organize any further negotiations. We have to exclude any further opening of the withdrawal agreement,” Tusk said. “But of course, we are staying here in Brussels and I’m always at the PM’s disposal.”

Juncker, captured by cameras earlier on Friday during an apparently heated exchange with May, said: “We have to bring down the temperature” around Brexit talks.

He said he did not mean to offend May and his comments describing the British position as “nebulous” referred to the broader state of the Brexit debate in the United Kingdom.

“We sypmathyse with Mrs May,” Juncker told a news conference. “I have the highest respect for the British PM.”

He added the EU, in answering May’s plea for more assurances on the Brexit deal so that she could get it past her parliament, promised to start negotiations with the UK on their new trade deal “the second after” their divorce deal is approved, so that the contentious Irish backstop hopefully never has to kick in.

Tusk also offered his words of respect.

“We have treated PM May with the outmost respect, all of us. We really appreciate the efforts to ratify our common agreement,” Tusk said. “We have treated PM May with much greater empathy and respect than some British members of parliament.”