Watch: Trump and Putin start their historic meeting in Helsinki with a handshake

Now the real fun begins.

US President Donald Trump and Russian leader Vladimir Putin have officially begun their summit in Helsinki — one of the most anticipated meetings between a US and Russian leader in years.

According to the White House’s schedule, both leaders will now meet one-on-one — with no other staff except possibly interpreters — for about 90 minutes. Then they’ll join some of their top aides for a two-hour bilateral meeting and working lunch. Finally, Trump and Putin will hold a joint press conference, the first between an American and Russian leader in about a decade.

The two presidents have a lot to talk about over the next three-and-a-half hours. They will likely discuss Russia’s meddling in the 2016 presidential election; how to wind down the war in Syria; Moscow’s annexation of Crimea and broader incursion into Ukraine; and how to reduce the number of nuclear weapons around the world.

But the real question is, how much will Trump actually confront Putin on any of these items? Trump still refuses to blame Russia for interfering in the 2016 presidential election and once implied Crimea might as well belong to Russia, because the majority of people there speak Russian — a talking point straight out of the Kremlin.

Just hours before his meeting with Putin, Trump tweeted “Our relationship with Russia has NEVER been worse thanks to many years of U.S. foolishness and stupidity, and now, the Rigged Witch Hunt!” — a reference to special counsel Robert Mueller’s investigation into possible Trump campaign collusion with Russia in 2016.

Putin, meanwhile, arrived late to Helsinki: his plane touched down just nine minutes before he and Trump were supposed to meet.

But now that the meeting has finally begun, it’ll be interesting to see what comes of their hours together — and whether either leader gets what they came for.

Watch Trump and Putin greet each other and Trump’s opening remarks: