Trade expert Stephen Jacobi says there are both risks and benefits to US President Trump's change of tune on the CPTPP.
Mr Trump is considering re-joining the CPTPP trade deal alongside New Zealand and other Pacific nations.
One major risk is that the United States tries to re-negotiate the text.
After the US withdrew from negotiations last year, American demands over Intellectual Property and Investor State Dispute Settlements were removed or watered down, Mr Jacobi said.
"The earlier TPP, with the US included, did not proceed because the US congress did not think it was a good enough deal for the US," he says.
"Subsequently, of course, President Trump withdrew. The deal has now been altered in ways that the US congress will approve of even less. That seems to me quite a significant obstacle," he said
"To put [the Intellectual Property and Investor State Dispute clauses] back in is like trying to put the genie back in the bottle. In particular, NZ would find it quite difficult to change tack and re-insert all those elements," he said.
TPP critic Professor Jane Kelsey wants assurances from the government that it would veto any moves to re-include those controversial clauses.
She says it won't be enough to treat the move as hypothetical as Parliamentary submissions on the deal close next week.
"The government needs to tell New Zealanders if it would veto the reactivation of the suspended items, such as those that would gut Pharmac's bargaining power with the pharmaceutical industry, and whether would it even consider discussing additional concessions to the US beyond the original TPPA," she said.
But there were possible benefits, said Mr Jacobi.
For instance, the 11 countries already in the deal now had potentially greater bargaining power with the US, he said.
"The US would have to pay more in the negotiations as well, and NZ would certainly want more agricultural market access to the US."
Mr Jacobi said countries should not let discussions with the United States slow the deal's implementation. CPTPP requires at least six of the 11 countries to ratify the text before it enters into force.
"It would be a disaster for everyone if that slows down," he said.