"The JFA decided to participate in the Copa America today," Japan Football Association (JFA) general secretary Kozo Tashima was quoted as saying by the Kyodo news agency on Thursday.
"We are in the process of notifying Conmebol (South American football confederation) as we speak."
Japan, who played as guests at the 1999 Copa America in Paraguay, were drawn with hosts Argentina, Bolivia and Colombia.
"Japan's confirmation was greatly welcomed in South America at such a special moment the Asian country is living through," the Conmebol said on its website.
It said the JFA asked Conmebol for its help "before FIFA for the release by clubs of at least 15 from a list of 20 Japanese players who play in European football."
The JFA decision to take up the guest spot in the July 1-24 event will not please European clubs who are reluctant to lose their Japanese players. Bundesliga side Schalke 04 have already objected to releasing defender Atsuto Uchida.
"We need to be careful how we reply if Uchida is called up in July," Schalke sporting director Horst Heldt said.
"We're always willing to cooperate with the JFA whether it's during the season or in the off-season.
"But we have a professional obligation to get the team in shape for an important and long season at that time of the year. It will be difficult for us to let him go."
The Kyodo report said J-League authorities had offered conditional support to the JFA decision, saying coach Alberto Zaccheroni could pick only one player from each club.
Tashima said he did not expect all of Japan's players to be available but the squad must be strong enough to protect the reputation of the country and the tournament.
"We need a team that won't embarrass us or damage the prestige of the Copa America," Tashima said.
"As (JFA President Junji) Ogura said, likely half the team would have to be from Europe.
"We don't expect to get all the players we want, and some we will need to rest. But we will try to pick as many of the players the manager needs."
