In a much -anticipated White House address, Obama was also expected to announce a plan to rebuild Iraq's splintered army.
He called Saudi King Abdullah, a pivotal member of the coalition he is building to battle IS, and gathered top defense and intelligence chiefs, while finalising a strategy for the kind of prolonged new intervention in the Middle East he has always abhorred.
Officials said Obama was also pressing Congress to sign off on USD 500 million in aid to equip and train "moderate" Syrian rebels, who would be on-the-ground partners for any US air campaign.
Obama will use his speech at 9 pm local Washington DC time (6:30 am local Indian time tomorrow) from the ceremonial state floor of the White House to warn that the fight against IS could be prolonged.
The New York Times said Obama was ready to sign off on air strikes in Syria to compliment those carried out on Islamic State targets in Iraq.
The White House would not confirm the report, but lent it credibility by refusing to deny it.
The plan would not just be a US effort but also involve US partners, Kerry said.
Obama has repeatedly told Americans, that after "ending" the US war in Iraq to honor a key campaign promise, he will not send US ground troops back into combat in the country.
But he has not ruled out sending US trainers to help prepare Iraqi forces -- stood up at the cost of billions of US taxpayer gollars after the 2003 US invasion.
But the complex sectarian stew facing Abadi was underlined when bombs killed 19 people in east Baghdad during Kerry's visit.
