MOSCOW, Russia - Russia will continue to boost its foreign exchange and gold reserves, adding more than $70 billion to its coffers in two years, Fitch Ratings predicted as it raised the country's credit rating to the highest level since 2014.

The international rating agency said that Moscow will be able to cope with new US restrictions against its financial sector. It comes shortly after Washington announced the latest sanctions targeting Russia over alleged involvement in the poisoning of double agent Sergei Skripal and his daughter in the UK last year. The measures include preventing American banks from participating in sovereign non-ruble primary bond issuance.

While Washington's restrictions could weigh on Russia's external financing flexibility, investment and growth prospects, the "heightened" sanctions risk has not stopped Fitch from upgrading Russia's rating to 'BBB' with a stable outlook from 'BBB- .'

"Russia has entrenched a credible and consistent policy framework that will deliver improved macroeconomic stability, reduce the impact of oil price volatility on the economy, and support increased resilience to external shocks," Fitch Ratings analysts said in a statement last week.

The nation's international reserves amounted to almost $520 billion as of August 1, according to the central bank's data. The figure will continue to rise and will reach $537 billion in 2019 and $591 billion by 2021, the agency forecast.

"Increased exchange rate flexibility and compliance with the fiscal rule support the economy's capacity to absorb real, financial and geopolitical shocks, and limit the impact of oil price volatility on the economy," Fitch said.

Russia's Finance Minister Anton Siluanov welcomed the upgrade by Fitch and said he hopes other rating agencies will follow suit.

"This decision [by Fitch] serves as another confirmation that Russia's economy has fully adapted to existing challenges and is capable of reaching new growth rates," Siluanov said.

"We hope that the decision by Fitch will serve as a logical basis for upgrading Russia's credit sovereign rating by other agencies of the 'Big Three' [Moody's and S&P Global]."

Russia's debt is rated at investment grade by all three big international rating agencies.

In February, US-based Moody's upgraded Russia's rating to investment grade (to Baa3 from Ba1) with a stable outlook. S&P Global Ratings upgraded Russia from junk level last year and has recently said the new US sanctions targeting sovereign debt will have no immediate impact on the nation's investment grade credit rating.