WASHINGTON: The United States (US) Navy awarded a $170 million contract for the manufacture of nine AH-1Z Viper Attack Helicopters to Bell Helicopter, the US Department of Defense said in a statement on Monday.

The combat helicopters will be manufactured and delivered to Pakistan under the Foreign Military Sales Program, the statement said.

The Bell AH-1Z Viper is a twin-engine combat chopper based on the previous SuperCobra model developed for the US Marine Corps, Sputnik reported. It has a top speed of 420 kilometres per hour and a range of 610km.

The contract awarded "for the manufacture and delivery of nine AH-1Z aircraft and nine auxiliary fuel kits for the government of Pakistan" is "expected to be completed in September 2018".

"Foreign military sales funds in the amount of $170,173,188 will be obligated at time of award," the Defense Department statement says, adding that the Naval Air Systems Command is contracting the activity for the Pakistani government.

Last April, the US State Department approved the Foreign Military Sale to Pakistan for the AH-1Z Viper Attack Helicopters and AGM-114R Hellfire II Missiles and associated equipment, parts, training and logistical support for an estimated cost of $952 million.

Read more: US approves billion-dollar arms sale to Pakistan

Earlier this year, the US approved a $700m sale of eight F-16 fighter jets to Pakistan, to which India strongly objected. The sale was made in order to improve Pakistan’s precision strike capability, the US said.

In a document released in February, the US administration told US lawmakers that its Foreign Military Funding (FMF) to Pakistan would focus on seven priority areas "identified and agreed to with the government of Pakistan".

These include "precision strike; air mobility and combat search and rescue; counter-improvised explosive device and survivability; battlefield communications; night operations; border security; and maritime security/counter-narcotics in support of counter-terrorism aims".

The document, sent to Congress with the US administration’s budget proposals for 2017, identifies these areas as essential to enhancing Pakistan’s counter-insurgency and counter-terrorism capabilities.