Britain's Prime Minister Theresa May is welcomed by European Commission President Jean-Claude Juncker at the EC headquarters in Brussels, Belgium December 8, 2017. REUTERS/Yves Herman

BRUSSELS (Reuters) - The second phase Brexit negotiations will be significantly harder than an already difficult first phase of talks, European Commission President Jean-Claude Juncker said on Friday.

The leaders of the 27 countries remaining in the European Union will give the go-ahead on Friday for the EU’s chief negotiator Michel Barnier to begin talks with London on a transition period and future trade ties with Britain.

“I have extraordinary faith in the British Prime Minister. She has agreed with me and Mr Barnier that the withdrawal agreement will first be formalized and will be voted on and then we will see. The second phase will be significantly harder than the first and the first was very difficult,” Juncker told reporters on arriving for the second day of the EU summit.