LONDON — When Britain’s foreign secretary, Dominic Raab, arrives in Washington for a visit this week, he will carry some extra baggage as an emissary: His country is eager to reach a trade deal with the United States, but his government just introduced a bill that would renege on a landmark treaty with the European Union.
That may not matter much to the Trump administration. President Trump has walked out of his own share of international agreements and is deeply hostile toward the European Union. His aides are likely to give a warm reception to Mr. Raab, a committed member of Prime Minister Boris Johnson’s band of Brexiteers.
But it could hurt Britain if the White House changes hands after November’s election.
Former Vice President Joseph R. Biden Jr. opposed Brexit and would make a trade deal with Britain less of a priority than Mr. Trump has. He is also a staunch defender of Ireland, which could ignite tensions if Mr. Johnson insists on the new legislation, which would revise how the Northern Ireland border is treated.
“Each administration, regardless of which political party they represent, brings with them different approaches,” Mr. Raab said an interview Monday in his office in Whitehall. “We’ve got the agility and sensitivity to deal with that.”
Mr. Raab defended the legislation — which would give Britain the power to alter customs procedures for Northern Ireland if it cannot agree on permanent trading arrangements with the European Union — as a “precautionary and defensive and proportionate response to what the E.U. is doing.”