He was working under the flag of the United Nations.

他在联合国工作。

《牛津词典》

Ships shall sail under the flag of one State only.

船舶应仅悬挂一国的旗帜航行。

youdao

So she wrote from her own warm and love childhood experience, from her own harmonious life, to look for a soul aegis for the world, under the flag of love and beauty.

她从自己充满温暖和爱的童年经历出发，从自我的和谐生活出发，在爱与美的旗帜下，为世人寻求一种心灵的庇护。

youdao

The two commanders met under a white flag of truce.

VOA: special.2009.11.19

"That's why the New York Yacht Club kept the Cup for 130 years, " says Koch, who competed under the flag of the San Diego Yacht Club.

FORBES: Magazine Article

The biggest threat to their chances of winning will come from an all-English trio of Jamie Staff, Matt Crampton and Jason Kenny competing under the flag of sponsors Science in Sport.

BBC: SPORT | Other Sport... | Cycling | Pendleton sets new British record

One of the things that we discussed is creating a mechanism so that the international community can ensure that we have a peaceful resolution of the situation there, and that any actions that are taken to protect civilians are done so not under the flag of any particular country, but that the international community is stepping in.

WHITEHOUSE: President Obama & President Medvedev Joint Press Conference | The White House