Russian President Vladimir Putin has sent 14 bomber aircraft on patrols far beyond its own territory, marking a permanent return to a Soviet-era practice.
Putin said the resumption of flights was a response to security threats posed by other military powers.
'We have decided to restore flights by Russian strategic aviation on a permanent basis,' Putin told reporters at joint military exercises with China and four Central Asian states in Russia's Ural mountains.
'In 1992, Russia unilaterally ended flights by its strategic aircraft to distant military patrol areas. Unfortunately, our example was not followed by everyone.
'Flights by other countries' strategic aircraft continue and this creates certain problems for ensuring the security of the Russian Federation,' Putin said.
Earlier this month, Russian air force generals said bomber crews had flown near the Pacific island of Guam, where the US military has a base, forcing US aircraft to scramble into the air to track them.
The Pentagon said the Russian aircraft had not come close enough to US ships to prompt American aircraft to react.
Many observers said the sorties, which had been stopped due to funding shortages in the Russian military, were a sign of Russia's growing assertiveness.
In recent years, President Putin has sought to boost defence spending in order to raise morale in the armed forces, which were starved of funding following the fall of the Soviet Union.
Under Mr Putin, the Russian Airforce is no longer in need of fuel, enjoys better maintenance and much higher wages.
This contrasts with the 1990s, when many pilots were grounded because there was no money to buy fuel.
The US has shrugged off Russia's decision, merely saying it was 'interesting'.
'That is a decision for them to take; it's interesting,' State Department spokesman Sean McCormack said after Mr Putin announced the resumption of the missions following a 15-year suspension.
