President Obama has called on Gulf nations to use their influence on Libya’s warring factions to help resolve the chaotic situation there.
He said those nations had been seen to “fan the flames of military conflict” in the North African country.
Libya has been in turmoil since the removal of former leader Muammar Gaddafi in 2011.
There are two rival governments and numerous militia controlling their own patches of territory.
Divisions have emerged among Gulf nations on Libya, with the United Arab Emirates (UAE) reportedly bombing Islamist targets in Libya and Qatar expressing reservations about such operations.
But Mr Obama said he crisis in Libya, where Islamic State has built a presence, could not be ended with “a few drone strikes or a few military operations”.
“We’re going to have to encourage some of the countries inside of the Gulf who have, I think, influence over the various factions inside of Libya to be more cooperative themselves,” Mr Obama told reporters.
“In some cases, you’ve seen them fan the flames of military conflict, rather than try to reduce them.”
The US president is due to host leaders of the six leaders of the Gulf Cooperation Council – from Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the UAE – next month at the White House.
People trafficking networks have thrived during Libya’s instability, making it the major departure point for migrants attempting the often dangerous journey to Europe.
President Obama was speaking alongside the Italian Prime Minister, Matteo Renzi, whose authorities have picked up more than 10,000 migrants in recent days.
Mr Renzi said the only way to solve the problem would be to restore stability to Libya.
“I think the Mediterranean is a sea and not a cemetery. The problem at this moment is the situation on the ground in Libya,” he said.
Among the latest to be rescued by the Italian coastguard were a group of 70 migrants, many of whom were badly burnt by a cooking gas canister explosion, the UN said.