U.S. President Barack Obama will meet with military leaders from some 20 countries to discuss strategy against Islamic State militants in Syria and Iraq.
The daylong meeting led by the chairman of the U.S. Joint Chiefs of Staff, General Martin Dempsey, is to begin at 3 p.m. local time at Andrews Air Force Base outside Washington.
It comes amid pressure on a U.S.-led coalition to halt the advance of the militant group, which made gains in Iraq's western Anbar Province and the besieged Syrian town of Kobani, on the Turkish border, on October 13.
Turkey is expected to be represented at the meeting, as are Arab states that have joined the United States in launching air strikes against the militants in Syria, such as Saudi Arabia and the United Arab Emirates.
Others expected to attend include representatives of Australia, Bahrain, Belgium, Canada, Denmark, Egypt, France, Germany, Iraq, Italy, Jordan, Kuwait, Lebanon, the Netherlands, New Zealand, Qatar, and Spain.
Dempsey's spokesman, Colonel Ed Thomas, said the meeting would be "about coming together in person to discuss the vision, the challenges, the way ahead."
He said no major policy decisions were expected.
Obama announced on September 17 that the United States and its partners would "degrade and ultimately destroy" the Islamic State (IS) militant group "through a comprehensive and sustained counterterrorism strategy."
But he has faced criticism from opponents at home over the campaign against IS.
Republican Senator John McCain, a frequent Obama critic, said on October 12 that "they're winning and we're not."
On October 13, Iraqi military officials said the militants forced Iraqi troops to abandon a military camp in Anbar Province and set it ablaze after looting armored vehicles and tanks.
The camp is some 8 kilometers from the town of Hit, which IS militants captured on October 2 in an advance across Anbar.
The United Nations said up to 180,000 people have been displaced by fighting in and around Hit.
Analysts say seizing the province would allow Islamic State to establish a supply line to start an offensive on Baghdad, the capital.
British Foreign Secretary Philip Hammond, on a visit to Iraq, warned on October 13 that the air strikes the United States, Britain, and others have been conducting since early August against IS targets in Iraq would not be enough to defeat the militants.
He said Iraqi security forces would have to do the "heavy work on the ground."
Monitors said IS fighters also advanced into a central area of Kobani, on Syria's border with Turkey, in heavy clashes with Kurdish defenders on October 13.
The Britain-based Syrian Observatory for Human Rights said the jihadists captured Kobani's cultural center as they pressed toward Kurdish holdouts in the heart of the city.
The U.S.-led coalition continued its air raids around Kobani.
But Turkish Foreign Minister Mevlut Cavusoglu denied any deal was reached between Washington and Ankara on the use of the Incirlik air base in southern Turkey for attacks against IS.
Cavusoglu said on October 13 that the matter, along with other open issues, remained under discussion.
U.S. national security adviser Susan Rice had said on October 12 that the Turks "have said that their facilities inside of Turkey can be used by the coalition forces" for attacks in Syria and Iraq.
With reporting by Reuters, AP, AFP, dpa, and BBC