New penalties targeting Russian “political officials” and rich elites close to President Vladimir Putin, known as oligarchs, will be unveiled on Wednesday, according to a top US official.

National Security Advisor Jake Sullivan told reporters aboard Air Force One, “We, the United States, will release a set of sanctions designations tomorrow that relate both to political persons, (and) oligarchs… as well as entities.”

President Joe Biden was on his way to the NATO and EU summits in Brussels to discuss Russia’s invasion of Ukraine.

According to Sullivan, Western countries are also attempting to “operate on sanctions enforcement so that Russian efforts to escape the penalties may be efficiently dealt with.”

Since Putin ordered troops into the neighboring country last month, Washington has imposed harsh sanctions on Moscow as well as a number of Russian businesses and individuals, as well as an embargo on Russian oil imports.

The restrictions have crippled the banking sector and financial system, causing the ruble to plummet, and prompting ratings agencies to lower the country’s debt and warn of a default by Moscow.

Roman Abramovich, the owner of Chelsea Football Club, has also been sanctioned by the United Kingdom and the European Union, but the United States has not followed suit.

According to the Wall Street Journal, Ukrainian President Volodymyr Zelensky requested Biden to refrain from going after Abramovich, suggesting that the Russian billionaire may help negotiate a peace accord with Moscow.