Pork producers in the United States, Australia and New Zealand urged their governments on Tuesday to push for an end to Canadian pork subsidies as Canada enters into talks on an Asia-Pacific free trade agreement.

"Canada needs to end its federal and provincial hog subsidy programs, which are distorting the North American and world pork markets," R.C. Hunt, president of the National Pork Producers Council, said in a statement with industry leaders from the two South Pacific countries.

The action came as the 13th round of negotiations on the proposed Trans-Pacific Partnership (TPP) were wrapping up in San Diego and the White House formally informed Congress that Canada would be joining future talks on the pact.

"On behalf of President Obama, I am pleased to notify Congress that we intend to include Canada in the ongoing negotiations of the Trans-Pacific Partnership agreement," U.S. Trade Representative Ron Kirk said in a letter to congressional leaders.

Because of tough issues ranging from proposed rules on the activities of state-owned enterprises to increased protections for workers and the environment, many trade policy specialists do not expect the TPP talks to finish until sometime in 2013.

The U.S., Australian, and New Zealand pork groups acknowledged domestic farm subsidy programs are not usually addressed by free trade pacts.

"However, in this case, Canadian agricultural subsidies are so wide ranging and have such a broad and far-reaching impact on overseas markets it is on these grounds we, along with the U.S. and New Zealand, urge the TPP negotiators and governments to deal with these issues fairly as part of the process," Andrew Spencer, CEO of Australian Pork Limited, said.

Both Mexico and Canada were invited into the negotiations last month by the nine TPP countries: the United States, Australia, New Zealand, Chile, Peru, Singapore, Malaysia, Vietnam and Brunei.

It is longstanding U.S. practice for the White House to formally notify Congress before entering into actual trade negotiations with any country.

Kirk sent a letter to Congress on Monday notifying of the administration's intention to include Mexico in the TPP pact.

Canada has long been the United States' largest trading partner, ahead of China and Mexico. Last year, two-way goods trade totaled nearly $600 billion.

Mexico and Canada are already free trade partners with the United States under the North American Free Trade Agreement, which went into effect in 1994.

In his letter, Kirk touted Canada's entry into the TPP as opportunity to update that 18-year-old pact with a "cutting-edge agreement ... that will further enhance our trade relationship and benefit U.S. workers, manufacturers, service supplies, farmers, ranchers, small businesses and consumers." (Reporting By Doug Palmer; Editing by Doina Chiacu)