Talks to reach a post-Brexit trade deal have been paused, because United Kingdom and European Union negotiators say "significant divergences" remain.
The chief Brexit negotiators for the European Union and the UK, Michel Barnier and David Frost, said conditions for a deal between the two sides have not been met.
State aid subsidies, fishing and enforcement of new rules remain the key sticking points in negotiations.
European Commission President Ursula Von Der Leyen and PM Boris Johnson will discuss the situation during the weekend.
Brexit happened on 31 January, with the UK leaving the European Union. But the rules didn't change at once, leaders needed time to negotiate a deal for life afterwards - they had 11 months to hold negotiations and strike a deal.
Both sides have to agree and ratify any deal by 31 December, when the current rules on EU-UK trade end. If they don't, they will do business on World Trade Organization rules, meaning the introduction of tariffs, or taxes on imports. So deal or no deal, there will still be changes.
Releasing identical statements on Twitter, Barnier and Frost said: "After one week of intense negotiation in London, the two chief negotiators agreed today that the conditions for an agreement are not met, due to significant divergences on level playing field, governance and fisheries.
Barnier is negotiating on behalf of the 27 EU member states and can only act within the mandate set by their leaders.
"On this basis, they agreed to pause the talks in order to brief their principals on the state of play of the negotiations."
A senior UK government source told BBC News the statement shows how far apart both sides are and that the trade talks have run into problems.
Earlier, Boris Johnson's spokesman said the government was "committed to working hard to try and reach agreement", but emphasised that the UK couldn't "agree a deal that doesn't allow us to take back control".
He added that "time is in very short supply, and we are at a very difficult point in talks".
Irish Prime Minister Micheál Martin said it was important for the 27 EU member states to give negotiators "the space to conclude these talks". He added that he "fervently hoped" a trade deal can be agreed.
Meanwhile, France's Europe minister, Clement Beaune, warned that his country could "veto" a deal if it did not satisfy their demands.
The European Parliament would need to ratify any deal before it can be implemented, and UK MPs are likely to get the chance to vote on legislation implementing the agreement. And the 27 EU national parliaments may also need to ratify an agreement - depending on the actual contents of the deal.