Trump demands Russia provide 'unambiguous answers' on nerve agent attack in UK

President Trump offered full backing Tuesday to the United Kingdom as it investigates the poisoning of a former Russian spy and his daughter with a nerve agent, and called on Russia to provide “unambiguous answers” on the subject.

Prime Minister Theresa May spoke with Trump about the incident, according to readouts from both the White House and 10 Downing Street, and reiterated that it was “highly likely” that Russia was responsible for the poisoning of Sergei and Yulia Skripel in Salisbury.

“President Trump said the U.S. was with the U.K. all the way, agreeing that the Russian government must provide unambiguous answers as to how this nerve agent came to be used,” a Downing Street spokesperson said.

The White House account of the call added that “the two leaders agreed on the need for consequences for those who use these heinous weapons in flagrant violation of international norms."

May told lawmakers in the House of Commons Monday that the pair were exposed to a nerve agent called Novichok and also said there that it was "highly likely" that Russia was responsible.

“This attempted murder using a weapons-grade nerve agent in a British town was not just a crime against the Skripals, it was an indiscriminate and reckless act against the United Kingdom, putting the lives of innocent civilians at risk,” May said.

The pair remain in critical condition following the March 4 attack in Salisbury. A police detective, Detective Sergeant Nick Bailey, who attended the scene was in stable but serious condition.

Skripal was recruited to spy for the U.K. after working in Russian military intelligence before being imprisoned by the Russians. He was freed in 2010 as part of a spy swap.

Russia has denied any involvement in the attack.

Trump had backed May earlier in the day, speaking to reporters before his departure for California, saying it sounds like Russia is responsible for the attack.

“It sounds to me that it would be Russia based on the evidence they have. I don't know if they've come to a conclusion but she's calling me today,” he said. “It sounds to me like they believe it was Russia and I would certainly take that finding as fact.”

Fox News' Serafin Gomez contributed to this report.