Congress will block a post-Brexit trade deal if it undermines Good Friday Agreement, Trump warned

The speaker of the US House of Representatives has said that a US-UK post-Brexit trade deal will be blocked by congress if it undermines the Good Friday Agreement.

Nancy Pelosi, whose Democrat party controls the House, said that Brexit must not endanger peace in Ireland.

Her comments follow those made by Donald Trump's US national securty adviser John Bolton who said the UK would be "first in line" for a trade deal with America.

He insisted the micro-deals would receive overwhelming "bilateral" agreement in congress.

He said: "The ultimate end result is a comprehensive trade agreement covering all trading goods and services," he said. "But to get to that you could do it sector by sector, and you can do it in a modular fashion. In other words, you can carve out some areas where it might be possible to reach a bilateral agreement very quickly, very straightforwardly."

But Pelosi warned: "Whatever form it takes, Brexit cannot be allowed to imperil the Good Friday Agreement, including the seamless border between the Irish Republic and Northern Ireland, especially now, as the first generation born into the hope of Good Friday 21 years ago comes into adulthood. We cannot go back."

She added: "If Brexit undermines the Good Friday accord, there will be no chance of a U.S.-U.K. trade agreement passing the Congress.

"The peace of the Good Friday Agreement is treasured by the American people and will be fiercely defended on a bicameral and bipartisan basis in the United States Congress."