MOSCOW, March 14. /TASS/. British authorities will step up checks on Russians coming to the country and freeze the state assets that could be used to threaten the UK’s security, the British Prime Minister vowed, addressing the parliament in connection with the Skripal incident.

"We will freeze Russian state assets wherever we have the evidence that they may be used to threaten the life or property of UK nationals or residents," May said.

However, a complete dissolution of dialogue between London and Moscow is not in British interests, she added.

Prime Minister Theresa May voiced several versions that might shed light on the use of the chemical agent presumably employed in Salisbury against former GRU Colonel Sergey Skripal and his daughter Yulia. In particular, she speculated that Russia might have lost control of that substance

"There are only two plausible explanations. Either this was a direct act by the Russian state against our country, or conceivably the Russian government could have lost control of the military-grade nerve agent and allowed it to get into the hands of others," May presumed.

May revokes invitation for Lavrov to visit UK

The British PM has rescinded an invitation for Foreign Minister Sergey Lavrov to visit the United Kingdon.

"We will suspend all planned high level bi-lateral contacts between the United Kingdom and the Russian Federation. This includes revoking the invitation to Foreign Minister Lavrov to pay a reciprocal visit to the United Kingdom," she said. 

Royal family not to attend 2018 World Cup in Russia

UK ministers, and the Royal Family would not visit the 2018 World Cup in Russia, the British PM said.

"So we will suspend all planned high level bilateral contacts between the United Kingdom and the Russian Federation," she said.

"This includes revoking the invitation to Foreign Minister [Sergey] Lavrov to pay a reciprocal visit to the United Kingdom...…and confirming there will be no attendance by ministers - or indeed members of the Royal Family - at this summer’s World Cup in Russia," May said.

On March 12, May demanded that Russia provide a clarification concerning the Skripal incident by the end of the day on March 13, warning that otherwise London would consider it to be "an unlawful use of force by the Russian state against the United Kingdom."

Russia did not provide the information the UK had demanded, pointing out that London had failed to provide samples of the substance used in the attack and slammed London’s statement as an unacceptable ultimatum. Russian Foreign Minister Sergey Lavrov said that Moscow had nothing to do with the poisoning of Skripal and his daughter. He stressed that in accordance with the Chemical Weapons Convention, the United Kingdom had had to immediately contact the country suspected of using such a substance, providing it with access to the substance in question. According to Lavrov, the Convention stipulates that an answer to such a question must be given within a period of ten days.

Skripal, 66, and his daughter Yulia, 33, suffered from the effects of an unknown nerve agent on March 4. They were found unconscious on a park bench near the Maltings shopping center in the city of Salisbury. Both are currently in the hospital and in critical condition. May said it was highly likely that Russia was responsible for the attack on Skripal and his daughter. She claimed that the substance used in the attack was a Novichok-class nerve agent developed in the Soviet Union.