The U.S., U.K., Germany and France on Thursday issued a joint statement blaming Russia for the nerve agent attack on a former Russian spy and his daughter in Salisbury, England, last week.

“We, the leaders of France, Germany, the United States and the United Kingdom, abhor the attack that took place against Sergei and Yulia Skripal in Salisbury, UK, on 4 March 2018,” the governments said.

“This use of a military-grade nerve agent, of a type developed by Russia, constitutes the first offensive use of a nerve agent in Europe since the Second World War," they added.

ADVERTISEMENT

“It is an assault on UK sovereignty and any such use by a State party is a clear violation of the Chemical Weapons Convention and a breach of international law. It threatens the security of us all.”

The nations also called on Russia to fully disclose its Novichok nerve agent program to the Organization for the Prohibition of Chemical Weapons.

British Prime Minister Theresa May said earlier this week that it is "highly likely" that Russia was behind the attack against Sergei Skripal and his daughter.

The two remain hospitalized in critical condition.

May announced on Wednesday that the U.K. was expelling 23 Russian diplomats from the country following the attack.

Russia has denied involvement in the attack and has vowed to take swift retaliation against Britain.

U.S. Ambassador to the United Nations Nikki Haley Nimrata (Nikki) Haley'The soul' versus 'law and order' Author Ryan Girdusky: RNC worked best when highlighting 'regular people' as opposed to 'standard Republicans' GOP lobbyists pleasantly surprised by Republican convention MORE publicly blamed Russia for the attack on Wednesday, saying Moscow must "come clean" about its chemical weapons program.

White House deputy press secretary Raj Shah also said Wednesday that it "certainly appears" that Russia orchestrated the incident.

"The president did tell the prime minister on the phone yesterday the United States does stand 100 percent with our ally [the] U.K. on this matter," Shah said.