Members of a 72-nation coalition are set to meet in Washington this week after Daesh was ousted from their former de facto capital in Iraq.
The meeting aims to ensure battlefield victories do not, once again, evaporate amid new sectarian strife.
Iraq's prime minister declared victory over Daesh in Mosul on Monday, three years after the militants seized the city.
In neighbouring Syria, US-backed forces have entered Raqqa and are battling Daesh there.
Iraqi people celebrated the victory in Mosul out on the streets.
The militants coerced residents into following Daesh's ideology of Islam through use of brutal force.
After the announcement of the victory in Mosul, commander of the US-led coalition Stephen Townsend, pledged more support to Iraqi partners until Daesh was defeated in Iraq.
The battlefield advances are potentially a fatal blow to Daesh's self-proclaimed "caliphate," but also bring fresh challenges and risks, according to Western diplomats and US officials.
One concern, officials and diplomats said in interviews, is that Iran could fill the vacuum left by Daesh to expand its clout in both Iraq and Syria.
Another is that the region's Sunni Muslims, if not given a share of political and economic power, could be vulnerable to Daesh recruitment as the group reverts from one that holds territory to a shadowy, violent insurgency.
Trump's budget for fiscal year 2018, which begins October 1, would allocate $13 billion for the military fight against Daesh in Iraq and Syria.
TRT World 's Nicole Johnston who had been in Mosul to cover the developments from the battlefield since the operation began, shares her experiences.
Multi-pronged strategy against Daesh
The Washington meetings from Tuesday through to Thursday will focus on ways to intensify a multi-pronged campaign against Daesh, according to the State Department.
That campaign and the overall military strategy were set under Trump's predecessor, Barack Obama.
Trump's post-conflict strategy, as described by US officials, follows two tracks.
The US, they say, will support a robust Iraqi and UN-led effort to stabilise liberated areas in Iraq, where American officials say they have a reliable partner in Iraqi Prime Minister Haider al Abadi.
But amid Syria's ongoing civil war, Washington is pursuing a more cautious, localised stabilisation plan.
Initial stabilisation efforts are already underway in eastern Mosul, but officials said the western part of the city, where fighting was more intense, will be the greater challenge.
Nearly a million civilians fled the city, according to the UN.
"This was beyond our worst-case scenario and we’re still one step ahead," thanks to $1 billion in funding pledged last year, said Lise Grande, UN humanitarian coordinator for Iraq.
Across Iraq, 1.9 million people have returned home, Grande said.