Oil prices extended gains for a third session on Monday, with Brent rising above $80 a barrel to its highest in more than four months, as wider U.S. sanctions are expected to affect Russian crude exports to top buyers China and India.

Russia's Foreign Ministry on Saturday denounced new U.S. sanctions against Moscow's energy sector as an attempt to harm Russia's economy at the risk of destabilising global markets and said the country would press on with large oil and gas projects.

By Florence Tan, Siyi Liu, Chen Aizhu and Nidhi Verma SINGAPORE/NEW DELHI (Reuters) - Chinese and Indian refiners are scouring the globe for supplies of crude as fresh U.S. sanctions on Russian producers and tankers curb shipments to Moscow's top customers,

The U.S. Departments of Treasury and State Friday applied new sanctions on Russia's oil production and exports. Sanctioned were oil companies, 183 ships, dozens of oil traders, insurance companies and energy officials.

Chinese and Indian refiners will source more oil from the Middle East, Africa and the Americas, boosting prices and freight costs.

U.S. President Joe Biden's administration imposed its broadest package of sanctions so far targeting Russia's oil and gas revenues on Friday, in an effort to give Kyiv and Donald Trump's incoming team leverage to reach a deal for peace in Ukraine.