Sessions and Kislyak both attended a small VIP reception before Trump’s April 2016 foreign policy speech.

“Investigators on the Hill are requesting additional information, including schedules from Sessions, a source with knowledge tells CNN. They are focusing on whether such a meeting took place April 27, 2016, at the Mayflower Hotel in Washington, DC, where then-candidate Donald Trump was delivering his first major foreign policy address. Prior to the speech, then-Sen. Sessions and Russian Ambassador Sergey Kislyak attended a small VIP reception with organizers, diplomats and others.”

At the time of the speech, Sessions was already serving as Chairman of Trump’s national security advisory committee, which had only a few members.

“Donald Trump has named Alabama Sen. Jeff Sessions the chairman of his national security advisory committee, the Republican frontrunner’s campaign announced Thursday evening.  Sessions, who became the first senator to endorse Trump earlier this week, will advise the candidate on matters of foreign policy and national security.  ‘We need to understand the limits of our ability to intervene successfully in other nations,’ said Sessions, a member of the Senate Armed Services Committee, in a statement. ‘It is time for a healthy dose of foreign policy realism. In the Middle East, this means forming partnerships based on shared interests, not merely overthrowing regimes in the dangerous attempt to plant democracies.’”

Kislyak was one of only four ambassadors who attended the VIP reception and Trump’s foreign policy speech

“Ambassador Kislyak was one of four foreign ambassadors who attended the speech that day. We seated all four in the front row during the speech in deference to their diplomatic status…The Center for the National Interest extended equal treatment to the four ambassadors attending the event and invited each to a short reception prior to Mr. Trump’s speech.”