The United States on Thursday declared there is no justification for Russia's retaliatory expulsion of American diplomats.
Later Thursday, the White House issued a statement saying the action by Moscow "marks a further deterioration" of the relationship between the U.S. and Russia.
"The expulsion of undeclared Russian intelligence officers by the United States and more than two dozen partner nations and NATO allies earlier this week was an appropriate response to the Russian attack on the soil of the United Kingdom. Russia’s response was not unanticipated, and the United States will deal with it," the statement said.
WATCH: State Department spokesperson Heather Nauert on Russia's plan to expel US diplomats
The Under Secretary of State for Public Diplomacy and Public Affairs, Heather Nauert, also criticized Moscow's actions, which were announced earlier in the day by Russian Foreign Minister Sergey Lavrov.
"Russia should not be acting like a victim," the State Department spokeswoman added, remarking that the only real victims are those poisoned and inconvenienced by the March 4 release of a nerve agent in the British city of Salisbury.
Lavrov announced the expulsion of 60 U.S. diplomats in response to Washington ordering the departure of the same number of Russian envoys.
Russia also is closing the U.S. consulate in the city of Saint Petersburg, ordering it to cease operations in two days.
"It's clear from the list provided to us that the Russian Federation is not interested in a dialogue on issues that matter to our two countries," Nauert told reporters at Thursday's State Department briefing. "We reserve the right to respond."
The United States, along with more than two dozen other nations, has revoked the credentials of Russian diplomats the nations accuse of working as spies after Moscow was blamed for the nerve agent attack on former Russian double agent Sergei Skripal and his daughter, Yulia, earlier this month in Salisbury.
"The United States is better off with fewer Russian spies," Nauert told reporters at Thursday's State Department briefing.
All of the Americans declared persona non grata — 58 diplomats in Moscow and two officials of the consulate in Yekaterinburg — are to leave Russia by April 5.
Russia also is expected to expel diplomats from the other countries that took action against it.
Moscow denies responsibility for the nerve agent attack. It alleges that the attack was carried out by British intelligence services in order to make Russia look bad. Britain dismisses that allegation.
Expressing concern about deteriorating relations between the two nuclear powers, the United Nations Secretary-General Antonio Guterres is calling for Washington and Moscow to discuss their differences.
"During the Cold War, there were mechanisms of communication and control to avoid the escalation of incidents, to make sure that things would not get out of control when tensions would rise. Those mechanisms have been dismantled," Guterres told reporters. "I do believe that mechanisms of this sort are necessary again."
U.S. Ambassador to Russia, Jon Huntsman — who was summoned to the foreign ministry Thursday — told VOA that "our desire, of course, is to maintain dialogue on the issues that matter the most. Issues like strategic stability and arms control, which are not just a U.S.-Russia set of issues, but indeed impact the stability and the well-being of the entire globe."
British Prime Minister Theresa May, in a phone call this week with U.S. President Donald Trump, praised Washington's "very strong response" in the wake of the poisoning.
The White House said, "Both leaders agreed on the importance of dismantling Russia's spy networks in the United Kingdom and the United States to curtail Russian clandestine activities and prevent future chemical weapons attacks on either country's soil."
Meanwhile, Yulia Skripal is "improving rapidly" after the nerve agent attack and is no longer in critical condition, said Salisbury District Hospital Medical Director Christine Blanshard.
Sergei Skripal remains in critical condition, according to the physician.
British police say detectives believe the Skripals first made contact with the toxin at the front door of their home. They cautioned that those living in the neighborhood will see continued searches, but that the risk to the public remains low.
Margaret Besheer at the United Nations and Jamie Dettmer in Moscow contributed to this report.