TOKYO, April 21 - Japanese Prime Minister Shinzo Abe has sent a ritual offering to Yasukuni Shrine, seen by critics as a symbol of Japan's past militarism, media reported on Monday, in a move likely to further strain ties with China and South Korea.

Abe's latest offering comes just days before U.S. President Barack Obama's three-day visit to Japan from April 23.

Japanese media said Abe will not visit the shrine in person. Fourteen Japanese leaders convicted as war criminals by an Allied tribunal after World War Two are honoured there, along with Japan's war dead.

Visits by Japanese leaders to the Tokyo shrine have outraged China and?the Koreas, which suffered under Japanese occupation and colonisation in the 20th century. Beijing and Seoul have been highly critical of previous offerings made by Abe.