TOKYO (Reuters) - U.S. Agriculture Secretary Tom Vilsack sought on Wednesday to downplay the probability of Japan agreeing to fully reopen its market to U.S. beef during his visit to Tokyo this week.

"We believe we have a safe and quality product," Vilsack told reporters after speaking at a food security symposium hosted by the U.S. Department of Agriculture, adding that he also acknowledged and respected concerns of Japanese consumers.

Asked if he expected any deal to be agreed during his visit, Vilsack said it was important to continue dialogue and build on the bilateral relationship.

He denied that there was U.S. political pressure on Japan.

His Japanese counterpart, Hirotaka Akamatsu, who later spoke at the same conference, reiterated Japan's commitment to have food safety regulations based on scientific knowledge.

"Whether food safety is strictly secured is the issue," Akamatsu told reporters. "The Japan-U.S. relationship is important, but that does not mean food safety can be neglected."

"A good relationship is being able to express views that may be difficult to accept. Secretary Vilsack understands that," he said, adding that both sides maintained different stances.

Akamatsu is scheduled to meet with Vilsack on Thursday.

Ahead of his visit, Vilsack last week offered a cautious outlook on talks with Akamatsu, saying the new government in Japan, which took office last September, was one issue complicating discussions. He reiterated those remarks in Tokyo on Wednesday.

Vilsack is in Tokyo to promote farm exports from the United States to Japan, the world's largest net food importer. Japan was also the biggest export market for U.S. beef until mad cow disease, formally known as bovine spongiform encephalopathy (BSE), was found in the United States in December 2003, prompting Tokyo to impose a ban.

Tokyo resumed U.S. beef imports in 2006 but limited them to meat from cattle aged 20 months or younger, a stipulation that angers U.S. exporters who argue it has no basis in science and costs them billions of dollars in lost sales.

The American beef industry estimates the partial export ban costs it about $1 billion in lost sales per year.

But Japanese public concerns about U.S. beef remain, given that some cow body parts banned by Japanese import regulations have been found in beef shipments from the U.S. in the past.

The U.S. is the biggest exporter of agricultural products to Japan, accounting for nearly one-third of Japan's agricultural imports.

A report by the U.S. Meat Export Federation last month showed Japan accounted for 13 percent of U.S. beef exports in 2009, nudging up from 11 percent in 2008.

(Reporting by Chikako Mogi; Editing by Chris Gallagher)