These steps, a senior Trump administration official told reporters on the condition of anonymity Monday morning, were intended to let the Russian government know that "when you attack our friends, you will face serious consequences."
Removing these Russians, the official said, is also a bid to reduce the "unacceptably numerous" Russian intelligence officers who reside in the United States and spy on Americans.
The Russian individuals and their families will have seven days to leave the U.S.
"As we've stressed to Moscow, the door to dialogue is open," the official told reporters on a call announcing the latest U.S. moves. "But if Russia wants to improve relations, it first needs to acknowledge responsibility for this attack and cease its reckless behavior."
Let our news meet your inbox. The news and stories that matters, delivered weekday mornings.
In a statement Monday morning, the White House said these "actions make the United States safer by reducing Russia’s ability to spy on Americans and to conduct covert operations that threaten America’s national security."
On Monday afternoon, White House Deputy Press Secretary Raj Shah called Russia's chemical weapons attack "reckless" and "brazen," but would not declare it an act of war.
Asked why the Seattle consulate was being closed, a senior administration official cited the consulate's proximity to a U.S. submarine base in the area.
Russia's foreign ministry called the coordinated expulsion of diplomats an "unfriendly step" that "will not pass unnoticed" in a statement Monday, while Kremlin spokesman Dmitry Peskov reiterated Russia's position that it was not involved in the poisoning of the Skripals.
"We already stated and reconfirm that Russia has never had any relation to this case. We will be guided by the principle of reciprocity as before," Peskov said, adding that after an analysis, the Foreign Ministry would propose retaliatory measures for Russian President Vladimir Putin's consideration.
At the time the sanctions were announced, a senior national security official said the sanctions were "just one of a series of ongoing actions we’re taking to counter Russian aggression" and that "there will be more to come."
A National Security Council spokesman, asked whether Trump had spoken directly with Putin about the U.K. chemical agent attack, would not respond, repeating instead that the last time the two men had spoken was last Tuesday.
Shah, asked during Monday afternoon's White House press briefing dodging why the president had not brought up the ex-spy's poisoning during his call with Putin last week, said Trump had "raised a number of issues" during that conversation, pointing to "positive developments from that call" on nuclear arms.