Foreign ministers from 68 countries are meeting in Washington to decide on the next steps to defeat Islamic State.
The meeting hosted by US Secretary of State Rex Tillerson on Wednesday is the first such gathering of the US-led military coalition since the election of President Donald Trump in November.
Trump has vowed to make the fight against Islamic State a priority and directed the Pentagon and other agencies in January to submit a plan for defeating the militant group.
The militants have been losing ground in both Iraq and Syria, with three separate forces, backed by the United States, Turkey and Russia, advancing on the group's Syrian stronghold of Raqqa.
The meeting is the first of the international coalition since Iraqi government forces, backed by the US-led international coalition, retook several Iraqi cities from Islamic State last year and liberated eastern Mosul.
While the jihadist group is overwhelmingly outnumbered by Iraqi forces, it has been using suicide car bombs and snipers to defend its remaining strongholds.
Iraqi Prime Minister Haider al-Abadi, who met with Trump in Washington on Monday, said he had won assurances of more U.S. support in the war against Islamic State.
Discussions on Wednesday will also focus on how to help Mosul rebuild and ways to tackle Islamic State operations in Libya and elsewhere.
In Syria, the US-led coalition has been working with an alliance of Kurdish and Arab militias. Its current focus is to encircle and ultimately recapture Raqqa - Islamic State's base of operations in Syria.
SBS Viceland: Islamic State