Covering the economic and industrial might of Japan

Japanese Body Language -

頭におく[あたまにおく, atama ni oku] take under consideration

oku is to place or put. 

If you need to give something some thought, what better thing is there to do than to put it in your head.

When negotiating a deal and a decision is being called for, your Japanese counterpart might tell you they will give it some thought.

This is what they will say.