Anti-whaling activists released footage on Tuesday showing local Japanese fisherman dragging dolphins into a cove using nets and ropes as part of their annual drive hunt.
The footage was filmed on Monday by US environmental group, the Sea Shepherd Conservation Society, in a village in Southwestern Japan.
Drive hunt refers to the practice of herding the dolphins into a cove, where they are trapped and later killed.
US ambassador to Japan, Caroline Kennedy, condemned the practice last Friday in a twitter post where she tweeted that she was "deeply concerned by (the) inhumaneness of drive hunt dolphin killing".
But the Japanese government has defended the hunt and says the fishermen were acting "with accordance to the law".
"Dolphin fishing is a form of traditional fishing in our country," Chief Cabinet Secretary, Yoshihide Suga, said during a news conference in Tokyo on Monday.
"We will explain Japan's position to the American side," he added.
The hunt in the fishing village of Taiji has come under international criticism and was the subject of the Academy Award-winning 2009 film "The Cove."
The fishermen in Taiji say the hunt is part of their village tradition and call foreign critics who eat other kinds of meat hypocritical.