behind-the-scenes negotiations

Translations
закулисные переговоры
The deal was finalized after months of behind-the-scenes negotiations.
Сделка была заключена после месяцев закулисных переговоров.
Definitions
Discussions and arrangements that take place privately or secretly, often involving key stakeholders, to reach an agreement or resolve issues without public knowledge or scrutiny.
Words
negotiation

noun
переговоры