It's up to that country to cut emissions even if they accept that job on behalf of other countries.
But first, lets start on just not dumping plastic into oceans, building more coal plants, and generally not cutting emissions at all (China)
Then we can worry on the manufacturing like cement and steel (I believe we should make our own steel anyway)
The more stuff we make, the more control we have over the emissions during the process. Because apparently, other countries don't give a shit.
Go look at the countries that have cut emissions. https://www.cbc.ca/news/science/climate-change-co2-emissions...
That's the only metric that matters, anything else is propaganda for those who aren't.