enter into

formal

to start to become involved in something, especially a discussion or agreement:
They refuse to enter into any discussion on this matter.
not enter into sth

If you say that something does not enter into something else, it is not an important or necessary part of it:
The Council's opinion doesn't enter into it - it's up to us to make the decision.

The rebel leaders stated that they are willing to enter into dialogue with the government.
We are not willing to enter into open-ended discussions.
It's a complex discussion and I don't want to enter into it now.
It is not our intention to enter into an arms race.
The union has repeatedly said it will not enter into any such agreements.

(Cambridge Advanced Learner's Dictionary & Thesaurus からの enter into sth の定義 © Cambridge University Press)

ビジネス英語

to start to become involved in something, especially a discussion or an agreement:
enter into a deal/a contract/an agreement
(Cambridge ビジネス英語辞典 からの enter into sth の定義 © Cambridge University Press)

- Cambridge Dictionary