The US Treasury Department said Tuesday that it has imposed additional sanctions on five Kremlin-connected Russian individuals on top of sanctions announced by President Joe Biden.

They include Aleksandr Bortnikov, the director of the Federal Security Service and a permanent member of the Security Council of the Russian Federation, and his son.

Others include Sergei Kiriyenko, the first deputy chief of staff of the presidential office, and his son, and Petr Fradkov, the chairman and CEO of Promsvyazbank Public Joint Stock Company (PSB).

Biden earlier announced the first tranche of sanctions against Russia after Moscow recognized the breakaway regions of Luhansk and Donetsk in eastern Ukraine and sent troops to keep peace.

The sanctions target two large Russian financial institutions -- Corporation Bank for Development and Foreign Economic Affairs Vnesheconombank (VEB), PSB, and their 42 subsidiaries.

VEB and PSB can no longer do business in the US, are cut off from the US financial system, and all assets under US jurisdiction will be immediately frozen, the Treasury said in a statement.

"Today’s action constrains Russia’s ability to finance defense-related contracts and raise new funds to finance its campaign against Ukraine," it said.

"VEB and PSB are state-owned institutions that play specific roles to prop up Russia’s defense capability and its economy," it added.

While VEB has a $53 billion asset portfolio servicing Russia’s sovereign debt with a loan portfolio of over $20 billion, PSB services nearly 70% of Russia’s defense contracts and provides banking and personal finance to Russian military personnel, it noted.

In addition, the sanctions included five vessels owned by PSB -- two container ships, two oil tankers and one cargo vessel.

"We continue to monitor Russia’s actions and if it further invades Ukraine, the United States will swiftly impose expansive economic sanctions that will have a severe and lasting impact on Russia’s economy," Treasury Secretary Janet Yellen said in the statement./aa