The Trump administration will impose sanctions on Russia under a chemical and biological warfare law following the poisoning of a former Russian agent and his daughter in the United Kingdom earlier this year, the State Department announced Wednesday.
"The strong global response to the use of a chemical weapon on the streets of Salisbury sends an unequivocal message to Russian Federation that its provocative, reckless behavior will not go unchallenged".
NBC, a USA news network, cited a senior state department official as saying that the sanctions would be structured in two tranches. The measures are scheduled to go into effect on or around August 22, according to the State Department.
Also in March, Washington ordered the expulsion of 60 Russian diplomats, and the closure of Russia's consulate general in Seattle.
Two more people - Dawn Sturgess and Charlie Rowley - were subsequently treated for exposure to novichok after Ms Sturgess reportedly picked up a discarded perfume bottle thought to have contained the agent.
The sanctions are mandated under the Chemical and Biological Weapons and Warfare Elimination Act of 1991, which says the U.S. president shall tighten the penalties within 90 days unless Moscow provides "reliable assurances" that it no longer engages in such activities, and allows on-site inspections by United Nations observers. The US still wants to maintain relations with Moscow, despite the new sanctions.
The news came as Republican US Senator Rand Paul said he had delivered a letter from US President Donald Trump to Russian President Vladimir Putin proposing cooperation.