Mana Party leader Hone Harawira has penned an open letter to his "bruddah", United States President Barack Obama, expressing his discontent with the Trans-Pacific Partnership Agreeement (TPPA).

Hone Harawira's open letter to President Barack Obama. Source: Supplied

The former member of Parliament and Maori Party member started by addressing the leader of the Western World, "Hey hey, mah bruddah!!"

"Heard you were able to get back to your dad’s turangawaewae last week. Mean … hope you had a good catch up with the whanau," he wrote, before moving onto the TPPA.

We’re Maori ... and we want you to know that we don’t support the TPPA; in fact we hate the bloody thing - Hone Harawira

"I also hear you’re getting ready to endorse the Trans-Pacific Partnership Agreement, and I’m asking that you hold off, for now anyway."

The TPPA is a controversial proposed regional free trade deal between 12 Asia and Pacific countries, including the United States and New Zealand.

Mr Harawira said Obama might not know who he was but that was "OK because I’m not that important in the scheme of things, but my people are".

Hone Harawira Source: 1 NEWS

"We’re Maori. The indigenous people of a little country down here in the South Pacific called Aotearoa - you probably know it as New Zealand - and we want you to know that we don’t support the TPPA; in fact we hate the bloody thing."

He then referred Obama to the Treaty of Waitangi, "which was supposed to protect [Moari] rights".

If we have to fight this TPPA thing we will, and we’ll fight it till we beat it - Hone Harawira

"It didn’t unfortunately, and now we’ve got less than 3 million of the original 66 million acres we once owned. We’ve been trying to win our Treaty rights back ever since and it hasn’t been easy," he wrote, later comparing Maori to Native Americans.

"We want to be able to look after our lands, our forests, our rivers and our seas just like the Treaty said we could, not just for Maori but for everyone in this country, and we’re really scared that the TPPA is going to make our fight an impossible one."

Mr Harawira said Maori "aren’t even allowed to look at the TPPA before it gets signed off", adding "from what we hear it’ll compromise our sovereignty as Maori and as New Zealanders".

He concluded by asking Obama to "give us a break" and scrap the TPPA.

"In fact, come on down to Aotearoa and let's go fishing, have a feed and a few beers, and between the two of us I betcha we can come up with something that works.