Washington, May 14 (IANS): US President Joe Biden said that the country's fuel supply will take time to normalise as the operator of a key fuel pipeline has restarted operations after a cybersecurity attack.

"This morning Colonial reported that fuel is beginning to flow to a majority of the markets that they service and they should be reaching full operational capacity as we speak," Biden said at a White House briefing on Thursday.

"We'll not feel the effects at the pump immediately. This is not like flicking on a light switch. This pipeline is 5,500 miles long," Xinhua news agency quoted the President as saying.

He added that it will take "some time" for the pipeline to fully return to normal operations.

"We expect to see a region by region return to normalcy beginning this weekend and continuing into next week."

Biden urged Americans not to engage in panic buying while gas stations in the southeastern US continue to face significant outages.

"Don't panic, number one. I know seeing lines at the pumps or gas stations with no gas can be extremely stressful. But this is a temporary situation.

"As I said, we expect the situation to begin to improve by the weekend and into early next week, and gasoline supply is coming back online. And panic buying will only slow the process," the President added.

As of Thursday afternoon, 69 per cent of all gas stations in North Carolina, 51 per cent in Virginia and 49 per cent in Georgia were without any fuel.

The Colonial Pipeline Company temporarily halted all pipeline operations after the cybersecurity attack involving ransomware was detected on May 7.

The Colonial Pipeline is the largest refined-products pipeline in the US, transporting more than 100 million gallons of fuel daily on the East Coast.

Energy Secretary Jennifer Granholm tweeted on Thursday morning that the restart of the pipeline "went well overnight", and "this should mean things will return to normal by the end of the weekend".