(Reuters) - Oil prices extended gains on Tuesday as heightened concerns surrounding major producer Iran and potential supply disruptions overshadowed the prospect of increased crude supply from Venezuela.

Brent futures jumped $0.77, or 1.21%, to $64.64 a barrel, hovering at its highest since mid-November. U.S. West Texas Intermediate crude climbed $0.80, or 1.34%, to $60.30.

"The oil market is building in some price protection against geopolitical drivers," said PVM Oil Associates analyst John Evans, highlighting the potential exclusion of Iran's exports, trouble around Venezuela, talks around the Russia-Ukraine war and over Greenland.

Iran, one of the top producers of the Organization of the Petroleum Exporting Countries, is facing its biggest anti-government demonstrations in years. A government crackdown against protesters that a rights group says has killed hundreds and led to the arrest of thousands, drew a warning from U.S. President Donald Trump of possible military action.

Trump said on Monday that any country that does business with Iran will be subjected to a tariff rate of 25% on any business conducted with the United States. Iran exports much of its oil to China.

"With the U.S. and China having reached a trade truce, we question whether the U.S. would want to rock the boat again with additional tariffs on China," ING strategists said.

UNREST SUPPORTING BRENT'S PREMIUM

Brent crude oil's premium to Middle East benchmark Dubai rose on Tuesday to its highest since July as geopolitical tensions in Iran and Venezuela supported the global price marker, LSEG data showed.

"Unrest in Iran has added about $3-4/barrel in geopolitical risk premium in oil prices, in our view," Barclays said in a note.

Markets are also grappling with concerns of additional crude supply hitting the market due to Venezuela's anticipated return to exports.

Following the ouster of President Nicolas Maduro, Trump said last week Caracas is set to hand over as much as 50 million barrels of oil subject to Western sanctions to the U.S.

Global oil trading houses have emerged as early winners in the race to control Venezuelan crude flows, getting ahead of U.S. energy majors.