This is a matter of the utmost importance.

这是个极其重要的问题。

《牛津词典》

It is a matter of the utmost urgency to find out what has happened to these people.

当务之急是弄清楚这些人出了什么事。

《柯林斯英汉双解大词典》

As a matter of the utmost urgency, the world has to keep balance between over population and finite resources.

当务之急是，世界必须在过剩的人口和有限的资源之间保持平衡。

youdao

The only sure bet is that Mr Duhalde will do his utmost to postpone both a primary (now due in January) and an election while Mr Menem has any chance of winning either.

ECONOMIST: Argentina's collapse