The proposed sale would improve the security of an important ally in the Middle East, it added.
The US State Department on Thursday approved a almost Dollars one billion deal in new arms sales for Saudi Arabia and notified the Congress of the same.
A war powers resolution for Yemen that represented an attempt to insert congressional oversight into U.S. military operations in the deadly civil war there was defeated by a vote of 55-44 by the U.S. Senate on March 21.
A statement from the State Department on Thursday confirmed approval of "TOW 2B (BGM-71F-Series) missiles for an estimated cost of USD670 million" to the Kingdom. Prior to the meeting, the former said that Saudi Arabia was a "part of the solution" in Yemen, in the midst of a civil war in the country, which, according to experts, has killed thousands of civilians in airstrikes, initiated by Riyadh.
Meanwhile, Amnesty International, in a statement on Friday, said there "was extensive evidence that irresponsible arms flows to the Saudi Arabia-led coalition have resulted in enormous harm to Yemeni civilians".
According to Reuters, the sale - which became public as Saudi Arabia's Crown Prince Mohammed bin Salman (MBS) met with U.S. Secretary of Defense Jim Mattis - will include Tube-launched, Optically-tracked, Wire-guided (TOW) missiles.
Iran strongly condemns hostile remarks by Saudi Arabia's foreign minister, who has accused the Islamic Republic of supporting "terrorism" while on a trip to the United States.
The Saudi military offensive, which began in March 2015, has killed at least 10,000, displaced more than 2 million people and pushed Yemen to the brink of starvation.
The Saudi crown prince is in Washington for official talks at the White House on his first visit to the U.S., which is mainly aimed at pushing for an ambitious nuclear deal.
Salman, 32, is also expected to meet with leaders of Congress and Cabinet officials such as Defense Secretary James Mattis and Mike Pompeo, CIA director and Trump's new pick to replace Rex Tillerson as secretary of state.
According to the SIPRI report, which was released last week, Saudi Arabia increased its arms purchases by 225 percent over the past five years, importing 98 percent of its weapons from the U.S. and European Union countries.