The Azkals, who are gearing up for their first Asian Cup berth, announced Eriksson's appointment last week after the surprise departure of Three Lions great Terry Butcher in August.
"I don't know why he left in such a short time," Eriksson said in his first press conference in charge. "I am going to stay much longer than he did, that's for sure."
Butcher was named coach in June but lasted less than 50 days, saying he was not "able to make this work".
Eriksson, who coached England to successive World Cup quarter-finals, said he will be at the helm for this month's AFF Suzuki Cup and the Asian Cup in January.
But what would happen after that was unclear, with Azkals' manager Dan Palami saying Eriksson will initially handle the squad for the key tournaments and "a little bit after, maybe about six months".
"But we are looking at different areas where he can be part of the Philippine football scene even in a different capacity," Palami said, adding that talks are ongoing.
Eriksson, from Värmland in Sweden, became in 2001 the first foreigner to head England's football team, and has since also coached Mexico and the Ivory Coast as well as league clubs in Sweden, Portugal, Italy and China.
He takes charge as the Philippine team enjoys unprecedented success, having jumped as high as 111 in the Fifa rankings in May 2018.
Eriksson said he took the Philippines job with an open mind: "I thought why not, why not do something a little bit different from what I've done before."
The new coach began training with the Azkals, a slang term for stray dogs, on Sunday.
He and the team are focused on the AFF Suzuki Cup, the Southeast Asian championship, starting with a game against Singapore on November 13th.
"I think the pressure is on the whole team… to try to do better in the Suzuki Cup than the Philippines has done before. That means at least reaching the final," he said.
As for the Asian Cup, the coach acknowledged it would be a challenge to beat more established teams like South Korea and China.
"I could easily say win it. I don't know if it's realistic to think that for the first time but let's start with Suzuki Cup, that's first," he said.
