"We have had two bits of relatively good news overnight - optimism about the USA shutdown not resuming and optimism about a trade deal", said Societe Generale strategist Kit Juckes.
The operation was carried out "to challenge excessive maritime claims and preserve access to the waterways as governed by worldwide law", Cmdr.
Doss confirmed the sailings to CNN.
"All operations are designed in accordance with worldwide law and demonstrate that the United States will fly, sail, and operate wherever global law allows", said Doss.
Communist superpower China claims ownership over nearly all of the South China Sea - frequently slamming the United States and its allies for naval operations in the territory.
China's claims to the South China Sea were largely discredited by an worldwide arbitration tribunal three years ago. China has developed a military infrastructure, including long runways used by jet fighters and deploying anti-aircraft missiles, on what had been low-lying reefs. In January, the destroyer USS McCampbell challenged China's claims to the Paracel Islands.
The guided-missile destroyers USS Spruance and USS Preble sailed within 22kms of the Spratly Islands as part of what the US Navy calls a "freedom of navigation operation".
Negotiators from the two countries are meeting this week in Beijing, with USA officials pressing China to commit to deeper reforms to a state-driven economic model that they say hurts American companies.
"The relevant actions of the U.S. warships violated Chinese sovereignty and undermined peace, security, and order in the relevant sea areas".
She demanded the U.S. "immediately stop its provocative actions" after the two destroyers conducted what Washington called "freedom of navigation" exercises in the area.
In late September, the USS Decatur also sailed within 22kms of Gaven and Johnson reefs in the Spratly Islands as part of a similar freedom of navigation operation.
"The US action violated the Chinese laws and global laws, infringed China's sovereignty, damaged regional peace, security, and order", Foreign Ministry spokesperson Lu Kang said at the time.
In October, the destroyer USS Decatur had to maneuver to avoid a collision with a Chinese warship that came within 45 yards of its bow.
The ships sailed close by Mischief Reef, where China has built an airbase on reclaimed land, and the adjacent Second Thomas Shoal, which is occupied by the Philippines.
Mid-level officials began discussions on Monday (Feb 11) in preparation for two days of talks starting Thursday involving US Trade Representative Robert Lighthizer, Treasury Secretary Steven Mnuchin and Chinese Vice Premier Liu He.
The Chinese side immediately conducted verification and identification on the USA ships and warned them to leave, said the spokeswoman.