He said: "I don't expect detailed proposals in front of leaders this week, because clearly everyone realises that the negotiators need more time".
An EU official says no further negotiations are planned before an EU leaders summit on Wednesday.
The British government said it remained committed to making progress at the summit.
European Union chief negotiator Michel Barnier said the two sides could still not bridge a gap between his demands that Northern Ireland stay in the EU's economic zone and London's rejection of any checks on trade between the province and the British mainland.
This would involve Northern Ireland effectively remaining part of the European customs area, with checks taking place at ports and ferries between the region and the British mainland instead of at the border.
If Britain leaves the European Union without an agreement on future relations, there could be chaos - tariffs would go up on trade, airlines could no longer have permits to fly between the two sides, and freight could be lined up for miles at the borders as customs checks are restored overnight. Did Raab spike? Or did European Union diplos misjudge strength of British oppo? "But I know everyone is trying incredibly hard".
The EU has proposed a backstop that would mean Northern Ireland staying in the customs union, large parts of the single market and the EU VAT system - the United Kingdom has rejected this, instead proposing a backstop which would effectively keep the whole of the United Kingdom in the EU customs union for a limited period.
Eurosceptic lawmakers in her Conservative Party are also concerned about a backstop, fearing it could keep Britain in the EU's sphere of influence possibly forever and stop the country from striking new trade deals with the rest of the world.
The announcement of a deal had been expected to be announced on Sunday evening, but it later emerged that there was no agreement.
Former Brexit minister David Davis, who resigned his post in July, criticized the government for accepting "the EU's language on dealing with the Northern Ireland border" and said it was now up to senior ministers to use their influence.
May must also overcome considerable opposition to her Brexit plan from within her own party. If Davis' call for a rebellion is effective, the Cabinet meeting is likely to be fractious.
The former secretary said he did not believe in the plan.
Previously, both sides had agreed that Britain crashing out of the Union on March 29 next year with neither a divorce agreement nor a road-map to future ties would be an economic and diplomatic disaster. The EU seeks an open border and single European market between the two countries, which is Britain's fallback or "backstop" position.
"It must be rejected, and it must be rejected now", he wrote in Monday's edition.
Brexit negotiators have yet to seal a deal on Britain's divorce terms, officials said, after a flurry of meetings in Brussels on Sunday to try to secure a draft agreement before Prime Minister Theresa May arrives for a summit this week.
- Huawei pins hopes for growth on Mate 20 Pro - USA
- Newcomer Leonard scores 24 as Raptors beat Cavaliers 116-104
- Trump Sending Pompeo to Riyadh for Talks on Missing Journalist
- Beto O’Rourke adopts Trump insult, branding GOP opponent ‘Lyin’ Ted’
- Mega Millions, Powerball jackpots reach almost $1 billion combined
- Arizona health officials confirm 2 cases of rare illness paralyzing kids
- Can Manchester United win the Premier League this season?
- NBA Preview: It's the Warriors, and then everyone else
- United States newspaper publishes 'last piece' by Khashoggi
- Top US General Barely Escapes Deadly 'Afghan-on-Afghan' Attack