Ukraine has said to Russia, "OK, we'll give you $1 billion worth of military equipment if you give us gas".
Of course it is unlikely the conversation went anything like that, but that pretty much sums up negotiations between the Ukrainian and Russian defense ministries, Naftogaz Ukraine and Gazprom.
According to Naftogaz Ukraine's chief Oleksiy Ivchenko, the parties have been negotiating a new deal in the past three months aiming to exchange Ukrainian weapons and military hardware for Russian gas. He did not comment on what equipment is being offered.