Hillary Clinton and Donald Trump square off at the second presidential debate, in St. Louis. You can follow our live updates here.

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Donald Trump claimed that the US doesn't have borders. “We’re going to have borders on our country that we don’t have now,” Trump said. But enforcement along the US–Mexico border has never been higher. There are currently about 21,000 agents patrolling more than 6,000 miles of the nation’s borders.

Trump falsely claimed that Muslims in the United States are not reporting terror plots to the authorities. Trump cited San Bernardino where he said there were "bombs on the floor" of the suspects' apartment. There has never been any evidence that this was the case. You can read more about that here.

Trump: "I was against the war in Iraq.” No. He wasn't.

Donald Trump: "It has not been debunked. I was against the war in Iraq.” It has been, and he wasn't:… https://t.co/uFlIkkycTq

Trump said, "We don't know if it's the Russians doing the hacking." Trump just said "we don't know if it is the Russians doing the hacking." Ummm... no. https://t.co/qPZIDeV4tR

Trump said that the US has the highest tax rate in the world. Trump says AGAIN that the US has the highest taxes in the world. That's...untrue. https://t.co/RPCi3F9RoA

Trump falsely declared that "Aleppo has already fallen." The fight for Aleppo is currently ongoing, where the Russian and Syrian air forces are bombarding the eastern half of the city, which remains in rebel control. Some 275,000 civilians are still in place inside Aleppo and casualties are going untreated thanks to the targeting of hospitals and other health centers.

Trump says he didn't say "check out sex tape." he literally said check out sex tape https://t.co/BznNiwDxyn

Did Crooked Hillary help disgusting (check out sex tape and past) Alicia M become a U.S. citizen so she could use her in the debate?

Trump’s said the US took in "tens of thousands" of Syrian refugees. That is not accurate. On Aug. 29, 2016, the White House announced it had taken in exactly 10,000 Syrian refugees. Between 2011, when violence in Syria first erupted, and 2015, the total number of refugees the US took in from Syria was under 1,500.