Putin said the Kremlin’s chief concerns remained unanswered – guarantees from the West that NATO would expand no further and that Ukraine would never be permitted to join.

The rating actions followed the revision of Ukraine's outlook to Stable from Positive earlier this month.

The country's partners pledged over $4 billion in financial aid in a move to support Ukraine's economy.

Moscow has repeatedly denied it has any intention of invading Ukraine but has held several rounds of talks with Western countries and NATO on its demand for “security guarantees“ that the Atlantic alliance will expand no further and Ukraine will never become a member.

In his third conversation with the Russian president in two months,  Biden said Washington would respond "decisively and impose swift and severe costs" if Russia moved into Ukraine.