Tonga had initially been selected to stage the Games but was forced to withdraw its bid earlier this year due to financial concerns.
The Samoa Association of Sports and National Olympic Committee (SASNOC) will now work with the Samoan government to ensure the nation is prepared to host the Games.
SASNOC president Patrick Fepuleai said Games events will take place at facilities used during the 2007 Pacific Games and the 2015 Commonwealth Youth Games multi-sport event, both of which were staged in Samoa.
The Pacific Games take place every four years. Papua New Guinea hosted the most recent edition in 2015, with the Solomon Islands scheduled to host the 2023 event.
“Hosts normally have seven years, we have only 573 days or less than two years to July 6, 2019,” Fepuleai said, according to the Fiji Times newspaper. “We bid for these Games because we were confident we could do it based on two most important factors.
“One, all our facilities are in place, we will not be building any new ones, just minor renovations. The second factor was our government is fully behind and supported our PGA.”