Russian President Vladimir Putin (R) shakes hands with Chinese President Xi Jinping during their meeting in Astana, Kazakhstan, on June 8, 2017.

US Secretary of Defense James Mattis has warned that Russia and China are challenging America’s military dominance with technological advances, “placing the international order under assault.”

Mattis made the statement to the US House of Representatives Armed Services Committee on Monday as part of his testimony at a hearing on the Defense Department’s 2018 budget request.

“A return to great power competition, marked by a resurgent and more aggressive Russian Federation and a rising, more confident, and assertive China, places the international order under assault,” the Pentagon chief said.

He said the US military dominance in sea, land and air was being threatened with Russian and Chinese technological advances.

“Our command of the seas is threatened by long-range, land-based guided munitions battle networks designed to attack our ships at increasingly longer ranges. Our undersea superiority, unquestioned since the end of the Cold War, and a key competitive advantage, is challenged by both Russia and China,” he stated.

Mattis also said there was no indication that Russian President Vladimir Putin wanted a positive relationship with the United States, saying it had chosen to be a “strategic competitor.”

“At this time … I do not see any indication that Mr. Putin would want a positive relationship with us. That is not to say we can’t get there as we look for common ground,” he said.

Chairman of the US Joint Chiefs of Staff Joseph Dunford also said that the United States had an adversarial relationship with Russia.

Washington and Moscow have a number of diverging interests, including in Syria and Ukraine.

Mattis warned that North Korea is increasing the pace and scope of its nuclear weapons program amid escalating tensions between Washington and Pyongyang.

“The most urgent and dangerous threat to peace and security is North Korea” he said.

US senators on Monday reached a wide-ranging bipartisan agreement to impose new sanctions against Russia and limit President Donald Trump’s powers to lift the bans without congressional consent.

The financial penalties target what the lawmakers call “malicious cyber activity” by Russia, referring to the country’s alleged cyber attacks against the Democratic Party in last year’s presidential election.

They also take aim at individuals supplying weapons to Syrian President Bashar al-Assad’s government. The bans can also be applied to individuals tied to Russia’s intelligence and defense sectors.

The measures are part of an amendment to a broader anti-Iran bill that proposes a range of non-nuclear sanctions against the Islamic Republic over its defensive missile program.