Russia never meddles in internal affairs of its neighbours, or more generally any other country.
Not long ago, heavy US bombers flew over Kyiv and Odessa. These were planes from the US armed forces. They did not get to Ukraine coincidentally, especially because US Secretary of State Mike Pompeo was in Ukraine not long ago, where they signed a special document, which says that Ukraine is under the special protection of the US “against a potential Russian aggression.” Some Ukrainian officials wanted to keep this document secret, but the bombers thwarted that wish.
Recurring disinformation about American involvement in the conflict between Ukraine and Russia. No evidence of any secret documents. The war in Eastern Ukraine is a well-documented act of ongoing aggression by Russian armed forces, since February 2014. While three US Air Force B-52s did enter Ukrainian airspace on 4 September, it is hardly proof that a "special" agreement was signed between Mike Pompeo and Ukrainian President Volodymyr Zelensky. The US Air Force stated it was a part of a "vital integration training with Ukrainian fighters". Pompeo visited Ukraine in January 2020, where he said that the US would continue talking about "how we can provide continuing support to the Ukrainian people from the aggressions that Russia has undertaken over the past handful of years," but did not mention any agreement. Then, President Zelensky met Pompeo informally in Munich in September.