The top six Democratic contestants, viz. Vermont senator Bernie Sanders, Massachusetts senator Elizabeth Warren, former vice-president Joe Biden, former South Bend mayor Pete Buttigieg, Minnesota senator Amy Klobuchar and billionaire businessman Tom Steyer; met for the last presidential debate at Iowa before the state goes for poling for nomination on February 3.

The debate lasted for about two hours in which a wide range of policy issues, ranging from medicare and childcare to foreign policy and climate change were debated. Here is a look at moments that stood out.

Democratic debate
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Middle East on the boil

At a time of a major escalation in tensions between Iran and the US, the first question to be asked in the debate was on the Middle East. Sanders reiterated that he did everything to stop the war in Iraq, while Biden supported it at the time. "I took to the floor, I did everything I could to prevent that war. Joe saw it differently," he said.

When asked about US troops in the Middle East, Warren said: "We need to get our combat troops out", while Klobuchar said she would "leave some troops there". Buttigieg, an Afghanistan veteran, criticized President Donald Trump for sending more troops.

Issue of North Korea drew some laughs

When Biden was asked whether he would meet North Korean leader Kim Jong Un, with whom Trump has had two summits in the past, Biden replied: "I would not meet with the, quote, Supreme Leader who said, 'Joe Biden is a rabid dog, he should be beaten to death with a stick".

"Other than that, you like him?" Sanders quickly bounced back.

"Other than that, I like him, and he got a love letter from Trump after that," Biden responded.

A female president

Warren and Sanders entered the debate in the midst of a bitter conflict, in which Warren claimed that Sanders told her in 2018 that no woman can beat Trump in 2020, a claim Sanders refuted. Making a stronger case for a woman president, Warren said women in the debate had a better election record as compared to their male opponents. "The only people on this stage who have won every single election that they've been in are the women: Amy [Klobuchar] and me."

It was a difficult position for Sanders, who had a tough time defending that he didn't make a sexist remark on the one hand and arguing that he, a man, is a better choice to be president, on the other.

Climate change

The issue featured somewhat prominently in the debate. When asked about the US-Canada-Mexico free trade agreement, Sanders replied: "Every major environmental organization has said no to this new trade agreement because it does not even have the phrase 'climate change' in it. And given the fact that climate change is right now the greatest threat facing this planet, I will not vote for a trade agreement that does not incorporate very, very strong principles to significantly lower fossil fuel emissions in the world."

Sanders also connected the issue with the farming industry of Iowa. "The drought here in Iowa is going to make it harder for farmers to produce the food that we need."

Non-traditional foreign policy issues

In the wake of the US-Iran standoff, foreign policy was expected to be a major topic of discussion. The issue was taken a step forward by former mayor Buttigieg, who when asked about his foreign policy experience, replied: "The next president is going to be confronted with national security challenges different in scope and in kind from anything we've seen before". Those security challenges, includes, "not just conventional military challenges, not just stateless terrorism, but cyber-security challenges, climate security challenges, foreign interference in our elections", according to Buttigieg.

Handshake rejected

After the debate, when Sanders sought to shake Warren's hand, she didn't reciprocate. Instead, an exchange of words took place after which Sanders turned away.