UPDATE 3-Biden warns UK on Brexit: No trade deal unless you respect N.Irish peace deal
* Biden warns Johnson on Brexit
* Biden tells UK to uphold Northern Irish peace deal
* Congress cautions Johnson on a trade deal
* Johnson reaches deal with rebels on Brexit plan (Adds British minister on Northern Irish peace deal)
LONDON, Sept 17 (Reuters) - U.S. Democratic presidential candidate Joe Biden warned the United Kingdom that it must honor the Northern Irish peace deal as it extracts itself from the European Union or there would be no U.S. trade deal.
"We can’t allow the Good Friday Agreement that brought peace to Northern Ireland to become a casualty of Brexit," Biden said in a tweet.
"Any trade deal between the U.S. and U.K. must be contingent upon respect for the Agreement and preventing the return of a hard border. Period."
Johnson unveiled legislation that would break parts of the Brexit divorce treaty relating to Northern Ireland, blaming the EU for putting a revolver on the table in trade talks and trying to divide up the United Kingdom.
He says the United Kingdom has to have the ability to break parts of the 2020 Brexit treaty he signed to uphold London's commitments under the 1998 peace deal which ended three decades of sectarian violence in Northern Ireland between pro-British Protestant unionists and Irish Catholic nationalists.
The EU says any breach of the Brexit treaty could sink trade talks and thus complicate the border between the United Kingdom's Northern Ireland and EU-member Ireland.
Asked about Biden's criticism, British junior health minister Edward Argar said that he did not believe the Northern Irish peace deal was at risk.
NO TRADE DEAL?
Biden retweeted a letter from Eliot Engel, chair of the Foreign Affairs Committee of the U.S. House of Representatives, to Johnson calling on the British leader to honor the 1998 Good Friday peace deal.
Engel urged Johnson to "abandon any and all legally questionable and unfair efforts to flout the Northern Ireland protocol of the Withdrawal Agreement."
He called on Johnson to "ensure that Brexit negotiations do not undermine the decades of progress to bring peace to Northern Ireland and future options for the bilateral relationship between our two countries."
Engel said Congress would not support a free trade agreement between the United States and the United Kingdom if Britain failed to uphold its commitments with Northern Ireland.
The letter was signed by Representatives Richard Neal, William Keating and Peter King.
Johnson is pushing ahead with his plan.
His government reached a deal on Wednesday to avert a rebellion in his own party, giving parliament a say over the use of post-Brexit powers within its proposed Internal Market Bill that breaks international law. (Reporting by Guy Faulconbridge; editing by Sarah Young and Kate Holton)
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