Short answers, pulled from the story.
Barack Obama and Dmitry Medvedev met in Prague to sign the New START treaty on the 8th of April 2010. This event marked the culmination of months of diplomatic work between Washington and Moscow.
Each party could hold no more than 1,550 deployed strategic nuclear warheads under the New START treaty. Data released in September 2022 showed Russia with 1,549 deployed warheads while the United States held 1,420.
Ratification required sixty-seven votes in favor out of one hundred Senators in the U.S. Congress. The Senate gave its advice and consent by a vote of seventy-one to twenty-six on the 22nd of December 2010.
Vladimir Putin announced the suspension of Russia's participation during his Presidential Address to Federal Assembly on the 21st of February 2023. He claimed the United States continued developing new nuclear weapons which he said would be countered by Russian development.
Joe Biden and Vladimir Putin agreed via phone call to extend the treaty by five years on the 26th of January 2021. The State Duma voted ratification on the 27th of January while Antony Blinken announced formal U.S. agreement on the 3rd of February 2021.