DOHA: Qatar Airways announced Tuesday it has placed an order worth more than $2 billion for six Boeing planes, which it said reflected the airline's continued expansion in the United States.

A statement on the Gulf carrier's website said it had placed an order for two Boeing 747-8 Freighters and four 777-300ERs.

It added that the order was valued at $2.16 billion "at list prices".

"The order, a sign of the airline's continued expansion and contribution to the US economy, adds to the airline's current fleet of nearly 100 Boeing widebody airplanes and its more than 100 additional Boeing aircraft on order," read the Qatar Airways statement.

The announcement was made at Boeing´s manufacturing plant in Everett, Washington, in the US.

The decision to buy the new planes may be seen as strategically as well economically important.

Gas-rich Qatar has made it clear it is seeking further investment opportunities in the US.

In 2015, it said it would invest up to $35 billion in the United States over the following five years, after targeting high-profile acquisitions in Europe.

Last December, Doha also announced the fund would invest $10 billion in US infrastructure projects.

The purchase also comes at a time of high political tensions within the Gulf.

Qatar has found itself regionally isolated since June 5 after Saudi Arabia, the United Arab Emirates, Bahrain and Egypt cut all ties, accusing Doha of bankrolling extremists and being too close to Iran.

As part of the sanctions placed on Doha, they have stopped Qatar Airways use of their countries´ airspace.

Qatar denies the charges.