The DUP has welcomed the government's "renewed focus" on addressing its objections to the Brexit deal ahead of next week's third Commons vote.
The party has twice voted against the deal over concerns it would see Northern Ireland treated differently from the rest of the UK.
After talks with ministers in London, its Westminster leader Nigel Dodds said it was still seeking extra guarantees.
His party "wanted to get a deal but it had to be the right deal", he said.
Mr Dodds spent Friday afternoon in meetings with key cabinet figures - including Chancellor Philip Hammond and Environment Secretary Michael Gove - as the government seeks to persuade MPs to support its deal when it returns to the Commons.
The third "meaningful vote" on Mrs May's deal is expected by 20 March and, if agreed, the prime minister has promised to seek a short extension to the Brexit departure date of 29 March, after MPs voted in favour of a delay.
If it fails to gain support, having already been defeated in the Commons by large margins twice, Mrs May has warned a longer extension may be needed and the UK may have to take part in European elections.
The 10 votes provided by the DUP, which has a parliamentary pact with the Conservatives, are thought to be key to the prime minister securing her deal.