On Thursday, the United States announced the decision to expel Trepelkov in response to the expulsion of US Deputy Chief of Mission Bart Gorman.
"We regard the new expulsion as another unfriendly step aimed at reducing the Russian diplomatic presence in the United States. Our retaliatory measures are predictable", Antonov said in a statement published by the Russian Embassy.
"We have made a lot of efforts to stop the escalation imposed by the Americans. We urged the State Department to reconsider its position in order to avoid an exchange of blows. However, we faced a categorical refusal, accompanied by a threat to arrest our diplomat if he stayed even for one more day in Washington", the ambassador added.
On Thursday morning, Russian President Vladimir Putin announced the start of a special military operation to demilitarise Ukraine after the breakaway republics of the Donbass region asked for assistance in repelling attacks by Ukrainian forces.
In a recent televised address, President Putin said that the circumstances "require decisive and immediate action from us". According to the Russian president, all responsibility for the bloodshed will be on the ruling regime in Ukraine.
Western countries have fiercely condemned Russia's military operation and increased sanctions pressure on the Russian government.