The Trump administration will punish Russia with sanctions for poisoning an ex-spy living in Britain with a chemical weapon, the State Department said Wednesday.

Russia's currency, which was already facing its worst day against the U.S. dollar since April, sank even further after the sanctions were announced. The dollar touched its highest level against the ruble since November 2016.

A senior State Department official said Russia, along with U.S. allies, was informed of the new sanctions on Wednesday afternoon.

In a statement, spokeswoman Heather Nauert said the sanctions will go into effect around Aug. 22:

"Following the use of a 'Novichok' nerve agent in an attempt to assassinate UK citizen Sergei Skripal and his daughter Yulia Skripal, the United States, on August 6, 2018, determined under the Chemical and Biological Weapons Control and Warfare Elimination Act of 1991 (CBW Act) that the Government of the Russian Federation has used chemical or biological weapons in violation of international law or has used lethal chemical or biological weapons against its own nationals. "Following a 15-day Congressional notification period, these sanctions will take effect upon publication of a notice in the Federal Register, expected on or around August 22, 2018."

Secretary of State Mike Pompeo reportedly approved of the U.S.' official determination that Russia violated a decades-old international law in its use of the poisonous chemical weapon Novichok, NBC News reported on Wednesday, citing U.S. officials.

Skripal, a former Russian spy who became a double agent for the UK, fell into critical condition after being poisoned in Britain on March 4. His daughter Yulia, who was visiting him from Moscow, was also poisoned.

The U.S. would be willing to impose a second set of sanctions on Russia three months later, a senior State Department official said Wednesday, unless Russia can prove it has met certain criteria.

Those include no longer using chemical or biological weapons in violation of international law and allowing on-site inspections by the U.N., as well as providing other reliable assurances, the senior official said.

This story is developing. Please check back for updates.