The problem from the NI Protocol is seen as a major problem by unionist parties, with every one opposing the EU measure, which they say weakens the union with a customs border in the Irish Sea.
In a tweet on Monday Ms Truss said: “Following meeting with Maros Sefcovic [On Friday] my team is in intense talks this week to deliver practical solutions to: Protect Belfast Good Friday Agreement and political stability in NI; Ensure free flow of goods GB - NI; Defend sovereignty of decision-making for all.
Her message may be seen as a restatement of her non-negotiable conditions for a deal, following her meeting with the EU on the matter on Friday. The former UK lead on Brexit, Lord Frost has just stepped down from the position, which she has filled.
After the talks on Friday Ms Truss said there is a “deal to be done” with the European Union over the Protocol. Following her first meeting with European Commission vice-president Maros Sefcovic, she said they had agreed to hold further talks on January 24.
However she refused to rule out the possibility the UK could invoke Article 16 – suspending part of the arrangements in the protocol – if they could not agree a way forward.