To Conclude
To Enter Into
する verb
When you tighten things up and bind things together, it's hard to separate them again. That's why this word is used to conclude or to enter into important agreements, like treaties and contracts.
Note that this word is quite formal, which makes sense, given the contexts it’s usually used in.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
どうしてあの国が突然平和友好条約を締結したのか不思議に思うよ。
It’s strange, I wonder why those countries entered into a peace treaty so suddenly.
この条約を締結するのにかなり長い時間を費やした。
We spent a considerable amount of time to ratify this treaty.
供給元とパートナーシップ協定を締結することにしました。
We decided to sign a partnership agreement with the supplier.