It is not the first time Russians have turned up in Ukraine under suspicious circumstances.
Gorkov is currently the head of Russia's state national development bank.
Dana Rohrabacher, who once lost a drunken arm-wrestling fight with Putin, said he did not need any reminder to be cautious.
Russian lawmakers deny allegations that Russia was behind the hacking of the Democratic Party during the election campaign.
The U.S. president said Russia "ran over" Obama for eight years.
Vladimir Putin's spokesman said people should not believe newspaper reports as they could be fake news.
The Treasury Department said U.S. companies could make limited transactions with the FSB.
According to a ministry spokeswoman, the diplomat was purchasing cancer drugs at the time.
An uncorroborated report circulated by U.S. intelligence alleges Russian security agents watched Trump engaging in "perverted sexual acts."
Well armed masked units were accused of scare tactics by locals.
Kiev's SBU claims a Ukrainian national was attempting to recruit a double agent in the army.
The Kremlin confirmed Yevgeny Zynychev had left Kaliningrad for personal reasons.
The man has been accused of close ties to Russia.
Putin's appointee in the Tula region won 84 percent of the vote amid record low turnout.
Congress must take the lead in condemning and threatening Russia for its efforts to meddle in the U.S. president election.
Polish military police suspects Lieutenant Piotr Capala may have offered to spy on Poland.
Shots and two explosions were reported in St Petersburg Wednesday morning.
Ex-KGB man Sergey Ivanov is moving on to the post of transport envoy.
Lithuania's foreign minister said Russia is accusing the victim, Ukraine, of attacking.
Kiev says FSB agents and Russian armed forces shot at each other.
Intelligence agencies specialize in the manipulation of information, and Russia's are good at it.
'For Trump to praise Putin despite what appears to be a deliberate effort to try to affect the election I think raises national security issues,' Democratic nominee says.
Russia's intelligence service doesn't attribute blame for the widespread attack targeting government agencies, defense companies.
The Trump campaign reacted to the mounting fury over the GOP nominee's friendly stance toward Vladimir Putin.
Alexander Fishenko was sentenced to ten years for working as a Russian spy.
Authorities suspect the centers of illegal business activity.