Sri Lanka on Thursday welcomed the first Russian travellers aboard a new flight service that was launched after the bankrupt nation urged Moscow to help revive its beleaguered economy by sending tourists.

Russia was Sri Lanka's biggest source of visitors at the start of the year but arrivals nearly ceased after the invasion of Ukraine and as the Indian Ocean island weathered its worst-ever economic crisis.

A commercial dispute also saw direct flights between the two countries suspended for months, prompting then-president Gotabaya Rajapaksa to ask his counterpart Vladimir Putin to resolve the impasse.

Thursday's flight by Russian carrier Red Wings, carrying 398 passengers, was the first of a new biweekly direct service between Moscow and the southern port town of Hambantota.

"The start of flights to Sri Lanka is a new milestone... a remarkable event for Red Wings, passengers and our countries," the airline's general director Evgeny Solodilin said in a statement.

The route complements existing flights between Moscow and Colombo by Russian national carrier Aeroflot, which resumed in October after a four-month suspension.

Aeroflot stopped its flights in June after a court ordered its Airbus A330 seized over a commercial dispute with an Irish company.

The aircraft was released after government intervention but the incident led to a diplomatic spat that was only resolved after Rajapaksa called Putin to ask for the flights to be resumed.

Sri Lanka has maintained friendly ties with Russia despite Moscow's pariah status since the invasion of Ukraine.

It has also purchased discounted Russian oil, ignoring embargoes imposed by the United States and European Union.

Months of blackouts, rampant inflation and critical food and fuel shortages made life a misery for Sri Lanka's 22 million people earlier this year.

The government defaulted on its $46 billion foreign debt in April and is working to secure an International Monetary Fund bailout.

Rajapaksa resigned in July after fleeing the country when a huge crowd of protesters, incensed by the economic collapse and its resulting hardships, stormed his official residence.

His successor has scrambled to repair Sri Lanka's balance sheet by raising taxes and attempting to kickstart the hard-hit tourism industry -- a key source of critically needed foreign currency.