US President Barack Obama is in Japan for talks seen by many as a stepping stone towards one of the worlds biggest trade agreements, the Trans Pacific Partnership (TPP).
Obama arrived in Toyko on Wednesday at the start of a four-nation tour.
A trade deal has so far been hindered because Japan wants to keep import tariffs on what it says are protected products such as beef, sugar, dairy and wheat.
Japanese Prime Minister Shinzo Abe told parliament the talks had been tough but Japan wants to keep some tariffs.
“We are currently in the process of trying to create a situation so that it doesn’t mean there are no protected areas and completely no tariffs,” said Abe. “However, the negotiations are very difficult and so it is necessary for them to continue,” he added.
Many people gathered to rally against Obama’s visit to their country.
“I got the impression that Obama was coming here on business. I don’t really want to see him here,” said protester Mineko Mokudai.
Meanwhile Obama has assured Abe that the US sides with Japan over the islands at the heart of a territorial row with China.
A bilateral security treaty obliges America to defend Japan. That confirmation is likely to be welcomed in the country.