The head of an ultranationalist Japanese organization says his group is responsible for planting a stake bearing claims over the Dokdo islets next to a monument for wartime sex slaves in New Jersey.

Nobuyuki Suzuki wrote on his personal blog Monday that members of his organization drove the wooden stake stating “Dokdo is Japanese territory” into the ground next to the monument last Saturday. The monument was erected in memory of Asian women forced into sexual slavery by Japanese soldiers during World War Two.

Suzuki also said his group placed a similar stake outside the South Korean consulate general in New York last weekend, explaining both acts were committed to protest the South Korean government’s moves to denounce Japan.

Suzuki was banned from entering South Korea in July after he tied a wooden stake stating Japan's territorial claims over Dokdo to a statue in Seoul in June. The bronze statue of a young girl sits outside the Japanese Embassy in Seoul and was installed to memorialize Korean women forced into sexual slavery for Japanese soldiers during the Second World War.