BELGRADE, Oct 13 (Reuters) - Serbia will do everything

it can to protect its interests in the face of U.S. sanctions

against Serbia-based, Russia-owned oil company NIS,

its president Aleksandar Vucic said on Monday.

Washington announced sanctions in January against NIS,

Serbia's biggest oil importer and one of Russia's last remaining

energy assets in Europe, over Moscow's 2022 invasion of Ukraine.

A series of waivers, however, had delayed them until last

week, when NIS said that no further postponement was

forthcoming.

"Our Russian friends have understood our message. We

understood their interests. We will do everything, tactically

and strategically, in the best interest of Serbia," said Vucic

in a video post on Instagram.

The post followed what Vucic called "frank, open and sincere

talks" with Alexander Dyukov - CEO of NIS's parent company

Gazpromneft - and Russia's deputy energy minister

Pavel Sorokin.

"There will be no shortages of crude oil, its derivatives

and no energy crisis," he added.

Vucic did not specify the scope of measures Serbia could

undertake to secure unimpeded supplies of crude oil.

The decision on Thursday by the U.S. Treasury's Office of

Foreign Assets Control prompted the JANAF oil pipeline

from neighbouring Croatia, which supplies crude to the NIS

refinery near Belgrade, to cut shipments.

Without deliveries, NIS - Serbia's only refinery, accounting

for around 80% of all its oil products from gasoline to jet fuel

- will struggle to operate beyond November 1, Vucic said last

week.