WASHINGTON - The US has demanded an immediate halt to an offensive by the Libyan militia leader Khalifa Haftar on the capital, Tripoli.

The Secretary of State, Mike Pompeo, said the US was continuing to press Libyan leaders to return to political talks mediated by the UN.

Four days of fighting around Tripoli are reported to have left more than 20 people dead. The UN says its call for a humanitarian pause was ignored.

Government forces have threatened a counter-offensive against General Khalifa Haftar's stronghold in eastern Libya.

They've been reinforced by allied militia fighters from the city of Misrata.(FA)