U.K. Prime Minister Boris Johnson said the chances of reaching a trade deal with the European Union are “very good,” but warned that negotiations can’t drag on beyond July.

“I don’t think we’re actually that far apart, what we need to see now is a bit of oomph in the negotiations,” Johnson said in a pooled interview with Sky News on Monday after an hour-long call with EU officials aimed at rebooting the stalled negotiations. “We see no reason why you shouldn’t get that done in July.”

But EU Council President Charles Michel warned that the EU isn’t prepared to “buy a pig in a poke” as the U.K. tries to put pressure on the bloc to sign a deal quickly. In a Twitter posting, he reiterated that meeting the bloc’s demands for a level playing field between the sides will be “essential” for any accord—a sign that big obstacles to a deal still remain.

It was Johnson’s first direct intervention in the discussions since the U.K. left the bloc at the end of January and both sides were seeking to use the meeting to build an understanding that a deal is still attainable.

The two sides agreed that “new momentum was required,” according to a joint statement following the meeting. “They supported the plans agreed by chief negotiators to intensify the talks in July and to create the most conducive conditions for concluding and ratifying a deal before the end of 2020.”

Formal negotiations will resume on June 29 in a more intensive format than the previous series of talks every three weeks. The British government had been pushing for such an intensification.

The two sides also committed to “if possible, finding an early understanding on the principles underlying any agreement.” This will please the U.K. government, which had called for swift progress toward the outline of a deal.

Since negotiations started in March, both sides have struggled to make progress on a free-trade agreement and other aspects of their future relationship such as fishing rights and security cooperation.The U.K. still rejects the EU’s demands for a level playing field, which would bind Britain to some European rules in areas such as state aid and environmental law.

Johnson’s call with European Commission President Ursula von der Leyen, Michel and other EU officials, came after he formally ruled out extending the U.K.’s negotiating period beyond the end of the year. Failure to get a deal would see Britain and the EU trading on World Trade Organization terms, meaning the imposition of tariffs and quotas.