The current trade dispute between Asia's second and fourth largest economies has its roots in grievances dating from World War Two.
They had been sister cities since 1957.
The South Korean president spoke at an event commemorating 99 years of the March 1 Movement, one of the first public displays of resistance to the Japanese occupation of the Korean peninsula.
Researchers believe the footage adds to evidence of a 1944 massacre of 30 Korean women at the hands of the Japanese army.
The statue pays tribute to the estimated 200,000 women enslaved in Japan's military brothels during World War II.
Hirofumi Yoshimura said the American city should "treat this issue with careful consideration."
A hotelier's book denying the massacre also provoked rebukes from China and South Korea's Olympic committee.
Regional stakes high given North Korea's threat to test an intercontinental ballistic missile.
The issue of "comfort women" has been a longstanding sticking point in Tokyo-Seoul relations.
Tokyo offers Seoul $8.3 million in compensation for the "comfort women" forced into sexual slavery.