The EU is "fully behind" Ireland over the Brexit plan, but "still unconvinced" by U.K.'s latest proposal, European Council President Donald Tusk said on Thursday.
"Today I had two phone calls on #Brexit, first with Dublin then with London. My message to [Irish Prime Minister] Taoiseach @LeoVaradkar: We stand fully behind Ireland. My message to PM @BorisJohnson: We remain open but still unconvinced," Tusk said on Twitter.
Tusk's remarks came after Johnson on Thursday briefed British lawmakers about his new Brexit deal a day after its publication.
Johnson argued that the new plan is a "compromise," saying the government has "gone the extra mile" with the hope of striking a deal with the EU.
Varadkar said Boris Johnson’s plans for an alternative to the backstop “fall short in a number of aspects”.
Johnson’s new deal proposes Northern Ireland remain aligned with the EU customs arrangements for goods including agri-food through 2025.
Under the deal, customs checks would be done away from the border area on the island of Ireland, but there would be a customs border between the U.K. and Northern Ireland.
The deal also proposes giving the devolved Northern Ireland government -- which has yet to be formed since a 2017 election -- the right to decide whether to continue with the arrangement or abandon it.
The backstop clause of the previous withdrawal agreement, which was repeatedly rejected by Britain’s parliament, will be replaced by the new proposals if the deal is accepted.
The backstop was designed to keep the U.K. in the same customs territory as the EU as well as Northern Ireland closely tied to EU regulations until a solution is found to the border issues.
It was categorically rejected by the Democratic Unionist Party -- the biggest political party in Northern Ireland, and currently the de facto partner of the Tory government in Westminster.
The EU has repeatedly said any deal not approved by Dublin would not be accepted by the bloc. It also has said that they would not renegotiate the withdrawal agreement's backstop clause.
U.K. and the EU officials are set to meet during the next European Council summit on Oct. 17-18.
The U.K. is set to leave the bloc on Oct. 31.