How to watch tonight's Democratic presidential debate

CNN, in partnership with The Des Moines Register, is hosting the seventh primary debate at Drake University in Des Moines, Iowa.

The debate will be the final face-to-face gathering of the candidates before the February 3 Iowa caucuses. Six candidates are set to appear: former Vice President Joe Biden, former South Bend, Indiana, Mayor Pete Buttigieg, Minnesota Sen. Amy Klobuchar, Vermont Sen. Bernie Sanders, businessman Tom Steyer and Massachusetts Sen. Elizabeth Warren.

The debate is the first meeting of the candidates since Iran fired more than a dozen ballistic missiles at two Iraqi military bases housing US troops. The attack last week was retaliation after Iran's top general Qasem Soleimani was killed in a US airstrike in Baghdad. The debate will provide an opportunity for the candidates to focus on foreign policy as they make their presidential case to the American people.

What time is the debate?

The debate will air live at 9 p.m. ET on CNN.

How can I watch it?

The debate will air exclusively on CNN, CNN en Español, CNN International and CNN Airport Network and will stream live in its entirety, without requiring log-in to a cable provider, exclusively to CNN.com's homepage, across mobile devices via CNN's apps for iOS and Android, and via CNNgo apps for Apple TV, Roku, Amazon Fire, Chromecast and Android TV. The debate will also air live at DesMoinesRegister.com and Democrats.org, and can be heard on CNN's SiriusXM XChannels and the Westwood One Radio Network.

Who is debating?

Former Vice President Joe BidenFormer South Bend, Indiana, Mayor Pete ButtigiegMinnesota Sen. Amy KlobucharVermont Sen. Bernie SandersBusinessman Tom SteyerMassachusetts Sen. Elizabeth Warren

Who is moderating?

CNN's Wolf Blitzer and Abby Phillip as well as The Des Moines Register's Brianne Pfannenstiel will moderate.

Who didn't make the cut?

Colorado Sen. Michael Bennet

Former New York Mayor Michael Bloomberg

Former Maryland Rep. John Delaney

Hawaii Rep. Tulsi Gabbard

Former Massachusetts Gov. Deval Patrick

Businessman Andrew Yang

How was the stage decided?

In order to qualify for the debate, candidates needed to meet both polling and fundraising minimums. For the polling criteria, candidates needed to receive 5% in at least four DNC-approved national or early state (Iowa, New Hampshire, Nevada and South Carolina) polls, or receive 7% in two early state polls.

Candidates also needed to receive donations from at least 225,000 unique donors, and a minimum of 1,000 unique donors per state in at least 20 different states.

What happened at the last debate?

The last Democratic presidential debate in December took place in California, but it was all about Iowa. Buttigieg, Klobuchar and Warren are banking on a strong performance there on the path to the nomination.

Buttigieg faced the kind of sustained criticism he had largely avoided during his rise to the top of the polls in Iowa. Warren and Buttigieg had been circling each other for weeks leading up to the debate. Warren highlighted a recent Napa Valley fundraiser Buttigieg held in a "wine cave," where the mayor talked to donors under a chandelier with 1,500 Swarovski crystals. Buttigieg responded by pointing out that Warren had held high-dollar fundraisers as a Senate candidate, and that her decision to no longer do so is a new one.

After a series of unsteady debates, Biden was the most comfortable that he's been on the debate stage to date, a sign of renewed confidence in his status at the top of the Democratic pack nationally -- and that the smaller debate stage suits him.

Yang also proved he belonged on the stage -- particularly because of his ability to cut through politics and policy in humanizing terms. This was clearest when he was asked about being the only person of color on the stage, something that happened after New Jersey Sen. Cory Booker and former Housing and Urban Development Secretary Julián Castro failed to qualify for the debate and California Sen. Kamala Harris dropped out of the race.

He said: "It's both an honor and disappointment to be the lone candidate of color on the stage tonight."