The parties involved should exercise (self -) restraint and prevent the situation from getting worse.

有关各方应采取克制态度，防止事态扩大。

《新英汉大辞典》

We need to exercise restraint.

我们需要学会约束。

youdao

We hope both sides stay calm, exercise restraint and resolve disputes through consultation.

中方希望柬泰双方保持冷静、克制，通过协商解决分歧。

youdao

U.N.officials described it as a very serious incident and urged both sides to exercise caution and restraint.

VOA: standard.2009.09.11

and we are still urging both parties to exercise maximum restraint."

VOA: standard.2010.08.03

"In lieu of the LTTE releasing people the U.N.Secretary General has called upon the government of Sri Lanka to exercise maximum restraint as it carries the fight to the LTTE in order to protect civilian lives,".

VOA: standard.2009.05.11

"I want to appeal to the nation to remain peaceful and exercise restraint, " he said.

NPR: Pakistan's Bhutto Killed in Suicide Bomb Attack

Clinton asked that India "continue to exercise restraint, " and settle the Kargil crisis bilaterally through direct talks.

CNN: THE DANGER OF ESCALATION

North Korea ought to keep its pledge on denuclearisation and all parties should keep calm and exercise restraint.

BBC: Regional media: Anger over North Korea test