Sergey Kislyak, the former Russian Ambassador to the US and alleged spy, has been at the center of the FBI's investigation into Russia's interference in the 2016 election, including whether members of the Trump campaign colluded with Moscow to tilt the election in his favor.

But Kislyak, 67, was involved with Russian foreign policy in the US long before Trump even announced he was running for president. He's been at the forefront of US-Russia relations for decades.

Here's a look at Kislyak's life: