Feb 28 (Reuters) - Australian shares closed higher on Monday, lifted by mining and energy stocks as fresh Western sanctions against Russia for its invasion of Ukraine stoked worries about supply disruptions.

The S&P/ASX 200 index ended 0.7% higher at 7,049.1, extending gains to a straight session, even as broader Asian markets fell.

"Markets at the moment are still on edge," said Steven Daghlian, a market analyst at CommSec, adding the impact on commodities and fears of the Russia-Ukraine conflict escalating further affect Australia indirectly.

President Vladimir Putin put Russia's nuclear deterrent on high alert on Sunday in the face of a barrage of Western reprisals for his war on Ukraine, which said it had repelled Russian ground forces attacking its biggest cities.

Miners led the gains in Australia, rising 3.2% on strong iron ore prices as concerns grew that a prolonged armed conflict between Russia and Ukraine could curb global supply of the key steelmaking ingredient.

Sector heavyweights BHP Group and Rio Tinto rose 4.1% and 3.1%, respectively.

Gold stocks climbed 2.9% as gold prices rose towards their best month since May on safe-haven demand spurred by the deepening Ukraine crisis.

Newcrest Mining, Australia's largest gold producer, advanced 3.4%, hitting its highest in nearly four months, also buoyed by final approval for its deal of Canadian gold miner Pretium

Energy stocks rose about 1.4% as oil prices jumped, with Woodside Petroleum advancing 2.1%.

In other news, buy-now-pay-later firm Zip Co Ltd said it would buy U.S.-based Sezzle Inc in a A$491 million ($352.49 million) deal.

Investors will be looking out for clues this week from the Reserve Bank Australia's meeting and update on economic growth in Australia and the United states, Daghlian said.

Across the Tasman Sea, New Zealand's benchmark S&P/NZX 50 index edged 0.46% higher to 11,977.

($1 = 1.3930 Australian dollars) (Reporting By Navya Mittal in Bengaluru; Editing by Subhranshu Sahu)