BRUSSELS, Sept. 9 (Xinhua) -- European Commission Vice-President Maros Sefcovic said on Wednesday he will call for an extraordinary committee with his UK counterpart to elaborate and respond to the Commission's strong concerns on plans to overwrite the Brexit deal.

"I will call for an extraordinary Joint Committee on the Withdrawal Agreement to be held as soon as possible so that our UK partners elaborate and respond to our strong concerns on the bill," Sefcovic said during a press conference presenting the Commission's first-ever Strategic Foresight Report.

He said he had spoken on Tuesday to his UK counterpart, Michael Gove, responsible for the implementation of the Brexit deal, to seek assurances that the UK will fully implement with Withdrawal Agreement and the Northern Ireland protocol.

"Once the British government tables the bill, we will study it carefully and I believe that the joint committee would be the most appropriate venue for further discussion," the vice-president said.

The British government announced earlier Wednesday to bring to the UK parliament a new bill that could partially breach the Brexit deal reached with Brussels.

The Internal Market Bill is supposed to protect jobs and trade across the whole of Britain after the Transition Period ends, according to the UK government. But a BBC report said it could override parts of the Withdrawal Agreement that secured the UK's exit from the EU, in breach of international law.

European Commission President Ursula von der Leyen said she is "very concerned" about the UK's intention to breach the Brexit agreement.

"Very concerned about announcements from the British government on its intentions to breach the Withdrawal Agreement. This would break international law and undermines trust. Pacta sunt servanda (Latin words, meaning "Agreements are to be kept") = the foundation of prosperous future relations," she tweeted.

European Council President Charles Michel echoed: "The Withdrawal agreement was concluded and ratified by both sides, it has to be applied in full."

The Withdrawal Agreement was signed between the EU and the UK on Jan. 24 of 2020, setting the terms of the withdrawal of the UK from the EU. Britain ended its EU membership on Jan. 31 and at that moment the Withdrawal Agreement entered into force.

But the UK is still following EU rules during the transition period until Dec. 31 of 2020 to allow both sides to bridge differences on the post-Brexit relationship, and forge a permanent future trade deal.