WASHINGTON — The Democratic National Committee announced on Thursday that it will sanction 12 debates for the 2020 presidential primaries, with the first ones taking place next June and July, the committee's chairman, Tom Perez, said on a conference call with reporters.

Six of the debates will take place in 2019, Perez said, and six in 2020, with the final one in April. Perez said that none of the states with the first nominating contests — Iowa, New Hampshire, Nevada and South Carolina — would host a debate until 2020.

Given the potential size of the Democratic field, Perez said the DNC would split the debates into separate events on back-to-back nights, with participation on a particular evening determined by a random selection open to the public.

That’s in contrast to the early Republican presidential debates in 2016, when the GOP held an undercard debate on the same day before the primetime debate featuring the major candidates.

"We expect that large field, and we welcome that large field," Perez said. “Drawing lots strikes me as the fairest way to make sure everyone gets a fair shake.”

Criteria for presidential candidates to qualify for the debates, Perez added, would be based on polling and grassroots fundraising, though he declined to offer specific thresholds; those will likely be announced at later dates.

"This is the first step in an ongoing debate process," he said.

Perez also said the DNC would not bar candidates from participating in forums, but he said it would discourage them from appearing in debates beyond the 12 the DNC is sanctioning.

In the 2016 presidential cycle, the DNC came under fire from activists for sanctioning just six presidential debates — though more eventually took place — and for limiting some of the events to weekend nights.