Waitangi weekend celebrations have started with controversy this morning as one of the men charged with assaulting Prime Minister John Key at Waitangi in 2009 protested his entry to Te Tii Marae.

Wikitana Popata launched a protest directed at Prime Minister John Key and other dignitaries entering the marae, yelling through a loud hailer: "Why are you here? The enemy is amongst us."

Mr Popata and his brother John Junior Popata, nephews of Maori Party MP Hone Harawira, were convicted and each sentenced to 100 hours' community work for the 2009 Waitangi assault on Mr Key.

"He is the one responsible for stealing our lands and killing many of our rangatahi (young people)," said Mr Popata this morning. "We must become a free nation from this corrupt government... from these injustices that he's put upon our people.

Mr Popata called the Maori Party kupapa, the term meaning "traitor" that was used for Maori who collaborated with the Government during the 1860s New Zealand Wars.

Diplomatic service personnel crushed in around Mr Popata as Maori who participated in the powhiri ushered him into the whare.

Mr Key was accompanied by Maori Affairs Minister Pita Sharples and several of his own ministers including Bill English, Hekia Parata, Georgina te Heuheu and local MPs.

He and Dr Sharples were surrounded by a large security contingent.

Mr Popata's protest was not the first controversy of the morning as Hama Apiata, the chairman of the Waitangi Marae Maori Committee, earlier tried to evict the New Zealand Herald and a TV3 reporter from the marae grounds, saying TVNZ had paid exclusive rights for the coverage.

Others from the marae defended media, however, and said they were allowed to be there. Currently a bigger media contingent is waiting outside the gates.

In a controversial move, the Te Tii Waitangi Marae has demanded that media organisations wanting to enter the marae to cover the celebrations pay a $1000 koha (gift).

The move has incensed many, who claim it is a fee and not a koha, and have refused to pay up.

Maori warriors are currently waiting for John Key to come on to the marae. New Zealand First leader Winston Peters has arrived and is in the whare where the welcome is expected to take place.

Meanwhile, US Secretary of State Hillary Clinton has sent her best wishes to the people of New Zealand for Waitangi Day celebrations, saying Waitangi Day is a chance to look back at New Zealand's rich history.

In a message for the commemorations celebrating 171 years since the Treaty of Waitangi was signed in Northland in 1840, Mrs Clinton, on behalf of US President Barack Obama and the American people, sent her best wishes to the people of New Zealand.

Mrs Clinton said that while looking back at a rich history and cultural heritage, New Zealand could also celebrate the promise of a future and the strength of the friendship between the two countries.

"The United States and New Zealand share a vibrant partnership. From my first hongi, and during my entire visit to Wellington and Christchurch last November, I experienced for myself Kiwi hospitality and friendship.

"We will continue to broaden the special relationship between our two countries by partnering on a variety of issues, from curbing climate change and promoting women's rights to stopping the spread of nuclear weapons and material.

"I wish all citizens of New Zealand a happy Waitangi Day, and continued peace and prosperity in the coming year," she said.

Today after being welcomed onto the marae Mr Key was to begin a Rugby World Cup carving before attending a Waitangi National Trust board meeting and an iwi leaders' meeting later today.

He was also to attend the navy beat the retreat service on the Treaty House grounds later today before an early start tomorrow morning for the dawn service in the Whare Runanga meeting house in the Treaty House grounds.

Thousands of visitors have begun arriving at Waitangi for the weekend of celebrations.

The navy will have its biggest presence at Waitangi for several years with three ships, the Navy Band and a 100-strong guard.

The Anzac frigate HMNZS Te Kaha, the offshore patrol vessel HMNZS Otago and the inshore patrol vessel HMNZS Hawea, were all to anchor in the Bay of Islands in full view of visitors at the Treaty House grounds.

The Navy first paraded at the Waitangi treaty grounds in 1947 but reduced its presence as protests grew and flags on the flagstaff in the grounds were pulled down by protesters.

The navy are scheduled to conduct two ceremonial beat retreat ceremonies today and tomorrow.