"We are dealing with Putin's duplicitous violation of the INF Treaty", Mattis said.
Mattis said that American intelligence is seeing "a continued effort" by Russian Federation to interfere in American elections, after they meddled in the 2016 presidential election.
Mattis said the Trump administration and other North Atlantic Treaty Organisation allies have pressed Russian Federation repeatedly on un-democratic actions, but to no avail.
Secretary of Defense James Mattis said Saturday he believed Russian President Vladimir Putin again tried to meddle in US elections.
"We are going to stand with the 41 nations, largest wartime coalition in history, who are still committed to this effort", Mattis said at the Reagan National Defense Forum on Saturday.
During the forum, former Defense Secretary Leon Panetta said Russian Federation will continue to undermine its neighbors, but also the United States in order to project its strength. -Russian relationship has deteriorated over the last two years. And labeled him a "slow learner". "He is not recognizing that what he is doing is actually creating the animosity against his people, he's not acting in the best interest of the Russian people", the secretary said during Q&A following his keynote speech. In this December 1, the White house spokesman Sarah Sanders said that trump during an official dinner at the G20 summit still had an informal conversation with Putin.
Speaking in Buenos Aires, Putin told reporters Saturday there were no preconditions for future bilateral talks with Trump. Russian Foreign Minister Sergey Lavrov called the canceled Trump-Putin meeting a missed opportunity, saying it didn't "help settling a number of important worldwide problems".
"Mr. Putin clearly comes tight".