In an interview with broadcaster Kanal 24, Erdogan also said that the United States should not try to discipline Turkey though trade measures, adding that Turkey had its own measures prepared.
"If they take the S-400s then ... they would not get the F-35s and the Patriots", Summers said, referring to the Patriot surface-to-air missile system, which has a primary function of defending against ballistic missiles and has been presented as an American-made alternative to the S-400.
"The S-400 is a done deal, there can be no turning back".More news: LeBron James writes thank you message to Michael Jordan on shoes
In a speech in Munich last month, U.S. Vice President Mike Pence declared that the Trump administration has "made it clear that we will not stand idly by while North Atlantic Treaty Organisation allies purchase weapons from our adversaries".
The comments come as part of this week's back-and-forth between Ankara and Washington on the issue.
When asked about Turkey's role in the production of key F-35 components, Scaparrotti suggested that it was dispensable, and stressed that the United States would reconsider the sale of other weapons systems to Turkey. "So I would hope they would reconsider this one decision on S-400 - one system - but potentially forfeit numerous other systems and... one of the most important systems that we can provide".
Summers said those consequences would encompass losing US military sales to Turkey, including the long-awaited sale of the United States' new F-35 Joint Strike Fighter jet.More news: Brie Larson brings out Captain Marvel's humanity
FILE - A Lockheed Martin F-35 Lightning II fighter jet is seen in its hangar at Patuxent River Naval Air Station, in the eastern US state of Maryland, Oct. 28, 2015.
Ankara is slated to receive the S-400 later this year in hopes of making the system ready for use by 2020.
"I would just underscore the fact that this is a... huge decision for Turkey", he said regarding the F-35, adding: "But also to FMS (foreign military sales) and other systems we sell to Turkey as well".
Russian Federation has utilised the S-400 system in its military operations in Syria. He has previously criticized Ankara for not doing more in the fight against the Islamic State group, and was particularly vocal about Turkey's detention of an American pastor released last year.More news: Former Trump Campaign Chairman Paul Manafort Sentenced to 47 Months
The countries have since become increasingly cooperative over Syria, where both are entangled in ongoing military operations and political negotiations to end the war.