The Democratic National Committee announced Thursday that it will sanction 12 upcoming presidential primary debates, with the first ones taking place in June and July of 2019.

Six of the debates will take place in 2019, DNC Chairman Tom Perez said on a conference call with reporters, while the other six will be held in 2020, with the final one occurring in April of 2020. Perez announced that none of the states with the first nominating contests – Iowa, New Hampshire, Nevada and South Carolina – would host a debate until the 2020 calendar year.

Given the potential size of the Democratic field – more than 20 candidates, more than 30? – 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 to appear 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.