The United States government on Thursday imposed sanctions on 19 Russian officials and five groups for Moscow’s alleged interference in the 2016 American presidential election, Reuters reported.

The administration of President Donald Trump also accused Russia of a continuing operation to hack the US energy grid and other critical infrastructure, and spying on the United States, AP reported. Unidentified US security officials told the news agency that the Federal Bureau of Investigation, the Homeland Security Department and intelligence agencies had determined that Russian spy agencies and “others” were behind the attacks on the US energy sector.

The officials said Russia deliberately obtained access to US computer systems and then conducted “network reconnaissance” of industrial control systems that run the country’s factories and the electricity grid. They said the US government had helped energy firms “kick out the Russians” from all energy systems known to have been breached.

“These targeted sanctions are a part of a broader effort to address the ongoing nefarious attacks emanating from Russia,” US Treasury Secretary Steven Mnuchin said. He added that a new sanctions law would “hold Russian government officials and oligarchs accountable for their destabilising activities” and penalise them in future.

However, it is not known when the sanctions imposed on Thursday would take effect.

US-Russia ties are already under strain. On Thursday, the United Kingdom, the United States, France and Germany issued a joint statement holding Russia responsible for the nerve agent attack on a former double agent in Salisbury. The four nations called on Russia to submit all information about the attack.