The US Wednesday escalated sanctions against Russia over the Ukraine crisis, targeting firms in the financial, energy, and arms sectors of Russia.

The US also slapped sanctions on individuals it accused of undermining Ukraine’s sovereignty or misappropriating Ukrainian property, Xinhua quoted the Treasury Department as saying in a statement.

The sanctions prohibit American citizens from providing new financing to Gazprombank OAO and VEB, two major Russian financial institutions, and energy firms OAO Novatek and Rosneft, limiting their access to US capital markets, it said.

The US also targeted eight Russian arms firms, which are responsible for the production of a range of materials that include small arms, mortar shells, and tanks, and Feodosiya Enterprises, a key shipping facility in the Crimean peninsula.

Among the individuals sanctioned are four Russian government officials, including Sergey Beseda, a senior Russian Federal Security Service official.

The new sanctions are imposed because “Russia has failed to meet the basic standards of international conduct” and “continued to destabilise Ukraine and provide support for the separatists, despite its statements to the contrary”, said Under Treasury Secretary for Terrorism and Financial Intelligence, David S. Cohen.

By imposing sanctions on entities within the financial services and energy sectors, the US has increased the cost of economic isolation for key Russian firms that value their access to medium- and long-term US sources of financing, said the statement.

The new sanctions are the most punishing measures to date for Russia’s intervention in Ukraine, the New York Times quoted US officials as saying.

“We have said for quite some time that Russia’s failure to take some of the steps that would de-escalate the conflict in Ukraine put them at risk of facing greater isolation and greater economic consequences,” White House spokesperson Josh Earnest told a regular briefing before the new sanctions were announced.