Secretary of State Mike Pompeo raised the crisis in a call with Foreign Minister Sameh Shoukry of Egypt, a top backer of Libyan warlord Khalifa Haftar.
Pompeo and Shoukry discussed the "importance of supporting a UN-brokered ceasefire in Libya through political and economic talks," the State Department said.
The talks came as Foreign Minister Mevlut Cavusoglu of Turkey, the crucial backer of Libya's UN-recognized government, visited Tripoli.
Cavusoglu said a ceasefire should see the Government of National Accord exerting control of areas held by Haftar, who has suffered losses but still controls eastern Libya.
Amid the instability, the United States imposed sanctions on a Libyan national, Faysal al-Wadi, two of his associates and the Malta-based company Alwefaq Ltd on allegations of smuggling.
The Treasury Department said Wadi and his Maraya vessel have been smuggling fuel and drugs from Libya to Malta, gateway to the European Union.
"The United States is committed to exposing illicit networks exploiting Libya's resources for their own profit while hurting the Libyan people," Deputy Treasury Secretary Justin Muzinich said.
The order freezes any assets in the United States and opens the way for criminal prosecution over transactions with the individuals, company or ship.
Libya has been in chaos since a Western-backed uprising toppled dictator Moamer Kadhafi in 2011.
Haftar's violent bid to seize Tripoli has been backed by US allies Saudi Arabia, Egypt and the United Arab Emirates as well as Russian mercenaries.
The White House on Tuesday called for a solution that includes a withdrawal of all foreign military personnel.
The United States recognizes the Tripoli government but President Donald Trump caused confusion last year by praising Haftar.
sct/ft