* May to meet EU's Juncker at 0600 GMT in Brussels
* Irish official: hours from border deal
* Britain says Brexit talks ongoing
* UK needs a deal soon to move to trade talks in time
* DUP leader negotiated through the night - source (Recasts with May to meet Juncker, adds DUP source, paragraphs 1-4, 8)
BRUSSELS/LONDON, Dec 8 (Reuters) - British Prime Minister Theresa May will meet European Union chief executive Jean-Claude Juncker before dawn in Brussels on Friday as the two sides seek to clinch a deal to open talks on post-Brexit trade.
May will meet the European Commission president at 0600 GMT, with a news conference to follow half an hour to an hour later, the commission said.
May's Downing Street office said she would travel with Brexit Secretary David Davis and also meet EU chief negotiator Michel Barnier.
"The prime minister is travelling to Brussels for further meetings on the Brexit negotiations," a Downing Street spokeswoman said.
EU and Irish officials had said earlier that Britain and Ireland could be hours from agreement on a text outlining how they would run their post-Brexit land border on the island of Ireland, paving the way for a deal that would remove the last obstacle to opening free-trade talks with the European Union.
A carefully choreographed attempt to showcase the progress of Brexit talks collapsed at the last minute on Monday when the Northern Irish party that props up May's government vetoed a draft deal already agreed with the government in Dublin.
Since then, May has been scrambling to clinch a deal on the new UK-EU land border in Ireland that is acceptable to the European Union, Dublin, her own lawmakers and Northern Ireland's Democratic Unionist Party (DUP), which keeps her government in power.
DUP leader Arlene Foster negotiated through the early hours with May, a DUP source told Reuters. Foster would make a statement later on Friday, the source said.
Juncker's spokesman said late on Thursday: "We are making progress but not yet fully there ... Talks are continuing throughout the night. Early morning meeting possible."
A senior Irish official said talks were moving swiftly and that a deal was possible within hours.
"It is moving quite quickly at the moment," the Irish official told a British Irish Chamber of Commerce event in Brussels. "I think we are going to work over the next couple of hours with the UK government to close this off."
"I say hours because I think we are very close," the official said.
European Council President Donald Tusk has scheduled a media briefing for 7:50 a.m. (0650 GMT). His role in plans for an accord would be to confirm that EU leaders will aim to agree at a summit next Friday to open trade talks in return for May making "sufficient progress" on the outline of a divorce package with the European Union.
Moving to talks about trade and a Brexit transition are crucial for the future of May's premiership, and to keep trade flowing between the world's biggest trading bloc and its sixth largest national economy after Britain leaves on March 30, 2019.
But the EU will only move to trade talks if there is enough progress on three key issues: the money Britain must pay to the EU; rights for EU citizens in Britain and British citizens in the EU; and how to avoid a hard border with Ireland.
The EU says May has an effective deadline of Sunday night if she wants to seal a deal and hope to have agreement on trade talks in time for the EU summit on Dec. 15.
All sides say they want to avoid a return to a hard border between EU member Ireland and the British-ruled province of Northern Ireland, which might upset the peace established after decades of violence.
The DUP insists that Northern Ireland, as part of the United Kingdom, must leave the EU in the same way as the rest of the United Kingdom.
To clinch a deal, though, May must ensure she has the support of the DUP, whose leader told her bluntly on Monday that it would not support her minority government's legislation unless the Irish border draft deal was changed.
She must also convince her divided Conservative Party that the deal she makes is acceptable.
British Foreign Secretary Boris Johnson, a leader of the Brexit campaign, insisted that the whole of the United Kingdom must "take back control" when it left the EU.
"Whatever way we devise for getting on to the body of the (Brexit) talks, it's got to be consistent with the whole of the United Kingdom taking back control of our laws, of our borders and of our cash," Johnson told reporters. (Reporting by Alastair Macdonald in BRUSSELS and Guy Faulconbridge in LONDON; Editing by Paul Tait)