So he can explain why he supports Ukraine, but not freer trade with Ukraine, all while not "being" the GoC? Interesting message dance, especially on the world stage.
I'm going to offer a different, impossibly idealistic potential off ramp ....
Remember the "old days", when parties would be able to oppose each other's work, but be able to get together via back channels to sort out a "meet in the middle" solution.
In this case, could there be a way to word the one line in question on a way that would allow:
1) Team Blue to say, "carbon pricing's off the table, so we're happy to see freer trade continue with Ukraine,"
2) Team Red to say, "we are happy to see continued freer trade with Ukraine while, at the same time, doing what we can with willing parties to help the environment," and
3) Ukraine to say, "happy to keep doing freer trade with Canada"?
If there was the willingness to meet in the middle on all sides (blue & red), could this be done?
I know, I know - dare to dream ....