UPDATE 2-Canada's Trudeau says will keep exploring trade deal with China

(Adds Trudeau comment)

BEIJING, Dec 5 (Reuters) - Canada will continue to explore a free trade agreement with China, Canadian Prime Minister Justin Trudeau said, as it weighs its options after the United States threatened to pull out of the North American Free Trade Agreement (NAFTA).

Speaking after a meeting with Chinese Premier Li Keqiang on Monday, Trudeau said that if "done properly", such an agreement would benefit both countries and strengthen the middle class.

"It's an opportunity that makes sense for Canadian businesses," he said at the start of a five-day trip to China. "Canada is and always has been a trading nation. But the landscape of trade is shifting and we need to adjust to it."

Li said China remained open to exploring a free trade deal with Canada as part of joint efforts to safeguard world trade liberalisation and advance globalisation.

"We have an open attitude toward the process of negotiations, and an open attitude towards their contents," Li said.

Canada is considering whether to launch talks on a free trade deal with China, which wants a trade pact similar to the ones it has with Australia and New Zealand.

But Trudeau, aware of domestic unease at the idea, is moving slowly. Although polls consistently show Canadians are split over the merits of a trade deal, Canada needs to diversify exports to offset the possible damage done if the United States pulls out of NAFTA.

Speaking to reporters on Tuesday, Trudeau reiterated that a deal with China was not an "overnight process".

"And once we get to the stage of negotiating a trade agreement, that's going to take years, as well," he said.

Trudeau's visit, which began on Sunday, comes as plane maker Bombardier Inc is eager to win a breakthrough order from Chinese carriers for its CSeries jet, whose fuselage is made in China.

But the chance of sealing such deals has become more cloudy after Canada encouraged Bombardier to sell a controlling stake in the CSeries programme to Airbus <SE AIR.PA> rather than a Chinese firm.

"On the agricultural front, I'm pleased to announce the Canadian beef and pork will have greater access to the Chinese market," Trudeau said at the Monday briefing, without elaborating.

China has been loosening restrictions on beef imports this year to feed the appetite of the country's growing middle class for more Western food.

Trudeau said he also agreed with Li a joint statement that affirms a commitment to "mitigating the global threat of climate change" and lays out a plan for closer collaboration. (Reporting by Michael Martina; Editing by Nick Macfie)