Prime Minister Shinzo Abe sent a ritual offering to Tokyo’s war-linked Yasukuni Shrine on Saturday, the first day of its annual spring festival, shrine officials said.

Given the masakaki (sacred tree) offering made as prime minister, an apparent appeal to his conservative base, Abe is expected to avoid visiting the Shinto complex in person during the three-day festival. The spring and autumn festivals are regarded as the most important events on its calendar.

The shrine has been a source of friction with countries that suffered from Japan’s militarism during World War II because it honors Japanese leaders who were later convicted as war criminals, along with millions of war dead.

A cross-party group of lawmakers that makes regular visits to Yasukuni visited the shrine on Friday.

Abe’s move immediately drew flak from South Korea, whose foreign ministry released a statement saying Seoul is “deeply concerned” and found Abe’s actions “regrettable.”

There was no immediate reaction from China, which also views Yasukuni as glorifying Japan’s past militarism.

It was only last week the foreign ministers of Japan and China agreed to go forward with mutual visits by Abe and Chinese President Xi Jinping as a show of improving cooperation between Asia’s two powerhouses. The agreement was struck between Chinese Foreign Minster Wang Yi and Foreign Minister Taro Kono on April 15, the first ministerial meeting of its kind in more than eight years.

Abe and Xi have not held talks in the format of an official visit by either side since both men took office in 2012.

Abe last visited Yasukuni Shrine in December 2013, drawing fierce protests from China and South Korea and prompting the United States, Japan’s main ally, to express disappointment.