With the Irish border set to become the only land barrier between the United Kingdom and European Union, frustration is growing in Dublin, Belfast and Brussels as United Kingdom negotiators struggle to find a solution which avoids customs checks or even CCTV cameras on the border - a potentially explosive development on the politically sensitive frontier.
"The UK has given a cast-iron guarantee there will be no hard border, and no physical infrastructure on the border - and we expect them to honour that in all scenarios".
The bloc's unelected bureaucrats are still intent on forcing the United Kingdom into agreeing to a "backstop" if the border can not be kept completely open, which would cut the province off from the rest of the United Kingdom by locking it in to the bloc's Single Market.
DUP leader Arlene Foster welcomed the prime minister to Fermanagh, saying Mrs May will hear "how people see both challenges and opportunities for their sectors as we leave the EU".
Not simply to fall back onto previous positions which have already been proven unworkable, she will add.
"While she doesn't agree with the EU's wording in terms of the proposed Irish backstop to date, that doesn't mean that Britain isn't committed to a backstop".
No one wants a hard border, but six months from Brexit, there is no plan in place to prevent one.
Mrs May will also call on the European Union to evolve its position in kind and to not fall back on unworkabale ideas on the second day of her visit to Northern Ireland.
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People in the vicinity of the explosion who may have been covered in the steam are advised to bag and wash their clothing. On the subways, R and W trains are bypassing 23 St in both directions because of FDNY activity on 5 Av and 21 St.
During her visit, the prime minister is also due to speak to young people in Belfast about Northern Ireland's future.
Mrs May will again refuse to countenance any backstop that creates a divide between Northern Ireland and the rest of the UK.
"And, on that basis, I look forward to resuming constructive discussions".
The UK still needs to come up with a backstop that works.
She also appeared to respond to Johnson who reiterated in his resignation speech earlier this week that "technical solutions to make customs and regulatory checks remotely" existed.
Following a meeting with Barnier, new UK Brexit secretary Dominic Raab rejected suggestions the UK's position "hangs by a thread", and said "we're getting ready at home for the domestic preparations that we're making".
The Prime Minister's Chequers White Paper was criticised by Brexiteers in her own party, who bemoaned its strategy for a soft Brexit.
After quitting the cabinet, former Foreign Secretary Boris Johnson singled out her treatment of the border as the biggest mistake of her negotiations with the European Union for a smooth exit from the bloc next year.
Speaking ahead of her arrival, Mrs O'Neill accused the prime minister of attempting to renege on the commitments she made in December.
"We hope Theresa May gets the message when she's here that everything isn't rosy in the garden".