Labour MP Kelvin Davis asked his party's leadership for permission to travel to North Dakota to support "Standing Rock" protests but was told there was too much work to do at home.
The request comes after Maori All Blacks prop Kane Hames wrote "Standing Rock" on his arm when his team took on USA in Chicago over the weekend.
Protesters are fighting a new oil pipeline in Standing Rock, a Sioux Native American reservation in North Dakota. Activists say the pipeline could contaminate the tribe's water source.
Today, Davis said he had talked to the Labour leadership about travelling to the States to join protesters.
"I said it would be good to go to show we empathise with the situation over there. But it's just not to be.