Tillerson made the remarks a day after meeting with Russian Foreign Minister Sergei Lavrov on the sidelines of the ASEAN Regional Forum in the Philippines - their first meeting since the United States slapped harsh new sanctions on Russia last week.
Mr Tillerson's comments to Sergei Lavrov, Russia's Foreign Minister, come after Donald Trump has repeatedly declined to categorically say that Russia meddled in last year's presidential race, contradicting the conclusions of his own intelligence agencies.
The meeting was the first between the two since the sanctions were signed into law by Trump. The House of the Representatives and the US Congress legislated the sanctions law which was signed by President Donald Trump.
Hours earlier, Lavrov said he believed his US counterpart was ready to continue dialogue with Russian Federation on complex issues despite the bilateral tensions and the imposition of new USA sanctions.
Quoted by Reuters, Ryabkov said that "we will of course intensify work related to import substitution, reduction of dependence on USA payment systems, on the dollar as a settling currency and so on".
Tillerson said that he had tried to help Lavrov understand "just how serious this incident had been".
The sanctions are also aimed at stopping Russian Federation from meddling in USA elections, but Moscow denies ever doing this. He said he shared with Tillerson how Russian Federation planned to carry out the expulsions but didn't provide details to reporters.
USA secretary of state is scheduled to visit the region next week to push for downgrading of diplomatic engagements and exchanges with North Korea.
Although the Trump administration has indicated no specific action against Thailand, Mr Trump has ordered a study into the causes of United States trade deficits.
To date, more than 13.9 million Mir cards have been issued in Russia, to roughly 10 percent of the country's population, according to the Russian National System of Payment Cards.
By contrast, U.S. trade with the European Union totaled over $3.6 trillion in 2014, and trade with China was almost $687 billion, according to the U.S. Census Bureau.
The statement warned "Russia will respond accordingly in the future", though it added Moscow is ready to fix ties "if Washington abandons its confrontational line". Other issues discussed included the situation on the Korean Peninsula following the adoption of UN Security Council Resolution 2371 on August 5. Despite the striking back initiatives, Russian Federation keeps the positive tone in the relations with the United States.