The US has taken another step in the drawn out Trans Pacific Partnership Agreement.

A US Senate panel has voted to give President Barack Obama authority to "fast-track" the trade deal, but Professor Jane Kelsey from Auckland University terms it a demonstration effect to make it look like something is happening.

She says Mr Obama doesn't have the support of Congress and that's what's needed to get it over the line.

"This is a bit of smoke and mirrors to try and make it all look as if it's going to happen and get the other countries to be prepared to make the deal.

"It depends on two things. One is whether President Obama can get fast track, and secondly whether the US and Japan are able to reach a deal between themselves on agriculture and automobiles. Either one of those could hold it up."

Meanwhile, Chief executive Phil O'Reilly is confident about the turn.

He says if it looks like US politicians are supporting Barack Obama, it will give negotiators confidence to go ahead and complete the trade deal.

"It's likely also to improve the confidence of others to put their best and last offers on the table so this is one of the ways to get TPP up and hopefully it will now lead towards the end game of TPP in a successful conclusion."