By David Reid, CNBC

A close ally of Russian President Vladimir Putin has said U.S. sanctions against him and the state-owned firm he heads cannot succeed.

Sergey Chemezov is chief executive of Rostec, a Russian state corporation established in late 2007 to promote and export products for civil and defense sectors.The firm employs 453,000 people and in 2016 reported a revenue of $18.9 billion.

Chemezov was barred by the Obama administration from entering the United States in 2014. Rostec itself was also subject to U.S. sanctions following Russia’s invasion of eastern Ukraine.

Speaking at Dubai Airshow on Monday, the CEO said his firm is currently entered into contracts with governments and that meant that the U.S. would now have to impose sanctions against all countries with which the company dealt with.