“严重关切”常见的英文表达有 “express grave concern over/about” 或 “be gravely concerned about” 。
We express grave concern over the recent escalation of violence in the region. （我们对该地区近期暴力升级表示严重关切。）
The international community is gravely concerned about the humanitarian crisis in the affected area. （国际社会对受灾地区的人道主义危机严重关切 。 ）