"According to data that served as the basis for the [Obama] administration to make such a decision, security services' data, Russian diplomats allegedly participated in some activities to undermine the US presidential election in 2015 and spring 2016," Zakharova said.
"I would like to note that people who have worked in the US for just 2 months were included in the list of diplomats and diplomatic Russian missions in the United States. How could they in any way be involved in undermining the US election, as evidenced by the [US] special services, in 2015 and spring 2016, cannot be understood."
"In fact, we are talking not only about diplomats, but also about members of their families. That's 96 people, including children of school and pre-school age."
Moscow hopes that current sanctions are the last thing that the administration of outgoing US President Barack Obama did to spoil Russia-US ties.
"It's symbolic that it happened on December 29. Moscow announced a long-awaited ceasefire in Syria. Diplomats, military joined efforts to find common ground with our partners. It was hard… On the same day, on December 29, Washington announced the expulsion of Russian diplomats. It's some kind of a revenge for the failure of its own foreign policy."
"Hopefully, this is the last thing that the current administration did for the deterioration of bilateral relations. The last strange, unwise decision which is directed against the people, against the human joy, against the things which bring people around the globe together."
"The thing is that, sadly, this administration, the outgoing administration, it is not just on the wrong side of history, it is on the bottom," she noted.
Zakharova also said that Washington's decision to prohibit visits to Russian embassy's compounds in the US is "unprecedented."
She added that reports of Russia allegedly closing the Anglo-American school in Moscow, where children of US, British and Canadian diplomats are learning, as a retaliatory step is "another case of deliberate disinformation."
Earlier in the day, Russian President Vladimir Putin said that Russia "will not expel anyone" in response to US sanctions and will determine further steps in restoring ties with the United States depending on the policy of President-elect Donald Trump.
The foreign ministry spokeswoman said that Russia took into account interests of US diplomatic missions' staff when decising not to respond to US actions.
"Understanding that diplomacy is based on 'mirror' response measures and steps, we took into account very seriously and very seriously considered the issue of how our American colleagues and their families would feel," Zakharova said. "And, most importantly, their children, who are now preparing for the New Year and who are having Christmas holidays now, how they will be taken out of the academic process and how they will also have to pack all their belongings in 72 hours and go home in this way. [And we] made this decision."