Donald Trump's foreign policy test awaited as key decisions pending
"The White House will begin reviewing the recommendations," the official said on condition of anonymity.
Trump had demanded that top brass find additional ways to defeat jihadists who still control a swath of northern Syria and Iraq and have inspired attacks on the West.
That review is now complete, and Defence Secretary Jim Mattis was to present the findings to Trump's top national security advisors later Monday.
Trump made defeating the Islamic State group a key pillar of this election campaign.
The group is already on the back foot, losing territory around Mosul and with its self-declared capital of Raqqa looking increasingly vulnerable.
But Trump faces a string of difficult decisions if he wants to set up the United States to deliver a coup de grace.
President Barack Obama was reluctant to put significant number of US boots on the ground, fearing a repeat of difficulties in Iraq and Afghanistan.
Trump must decide whether to intensify Obama's air-and-ally based approach or deploy the might of the US military in a more decisive -- and potentially risky -- way.
He must also choose whether to back Kurdish-led forces who have shown most success in taking the fight to the Islamic State group in northern Syria.
So far the White House and the Pentagon are being tight-lipped about what options Trump is being presented with.
"Don't expect a big rollout of this as it is still preliminary and we don't want to telegraph our actions in advance to the enemy," said Pentagon spokesman Navy Captain Jeff Davis.