“I’m talking to David Frost again today,” Barnier said on Twitter, adding that he had tried to point out that the rest of the time should be used.
“Our doors are open,” Barnier tweeted.
The two negotiators also discussed on Monday, but without visible progress.
The EU delegation originally planned to travel to London this week to continue negotiations on a comprehensive trade agreement with Britain, but the face-to-face meeting was temporarily postponed.
The British government described the telephone conversation between Frost and Barnier as constructive, but noted that no major progress had been made.
“The situation is the same as yesterday and they will continue to keep in touch,” a government spokeswoman said.
European Union leaders last week called on Britain to intensify post-Brexit talks and “take the necessary steps to make the deal possible”, to which London responded with undisguised outrage.
The British Prime Minister Boris Johnson stated that he saw no reason to continue the talks, but did not suspend the talks.
The Prime Minister said that the negotiations should not continue until the EU shows a significant change in its approach.
The transition period after Britain’s withdrawal from the EU ends on 31 December, and there is very little time left to reach an agreement on the future of the two sides, as it has yet to be ratified by both parties.