The new commander of US Submarine Forces — Vice Adm. Charles Richard — stressed Friday that the US Navy is locked in "major power competition," but added that America's advantage beneath the waves will not erode on his watch.

Rival powers, China in particular, are attempting to bolster their submarine capabilities to challenge American military power, according to the head of Indo-Pacific Command.

Richard explains that " our nation expects and demands victory," reminding those in his command that "we shall not fail!"

As the new commander of US Submarine Forces took the reins Friday, he stressed that America will continue to dominate beneath the waves.

Vice Adm. Charles A. Richard relieved Vice Adm. Joseph E. Tofalo as head of US Submarine Forces and Allied Submarine Command Friday at a ceremony aboard the Virginia-class attack submarine USS Washington, according to a Navy release.

"The mission of our Submarine Force today is clear," Richard said. "We are back in a world in the midst of major power competition. In that competition our strength undersea is a key advantage that we have. That will not change on my watch. With so much at stake, we cannot let up and must execute our mission with a continued sense of urgency."

The Ohio-class ballistic missile submarine USS Tennessee returns to Naval Submarine Base Kings Bay, Georgia, U.S. Mass Communication Specialist 1st Class James Kimber/U.S. Navy/Handout via Reuters

"Prepare for battle! This was Admiral Tofalo’s direction, and it is mine as well," he added at the ceremony, "It is only by being prepared for battle that we can hope to avoid it. If we cannot, our nation expects and demands victory. We shall not fail!"

Richard's comment on major power competition echoes the Trump administration's focus on great power competition over other national security threats. "We will continue to prosecute the campaign against terrorists that we are engaged in today, but great power competition, not terrorism, is now the primary focus of U.S. national security," Secretary of Defense Jim Mattis said in January when he announced the 2018 National Defense Strategy, the first since 2014. The emphasis is now on China and Russia, with China being a particular point of concern.

The People's Liberation Army Navy is the largest naval force in Asia, and China has made the modernization of its submarine force a priority, according to a 2017 Department of Defense report, which noted that China had, at that time, an undersea force of five nuclear-powered attack submarines, four nuclear-powered ballistic missile submarines, and 54 diesel-powered attack submarines.

Chinese Navy nuclear-powered submarine sails during an international fleet review Guang Niu/Associated Press

China's submarine force is expected to grow significantly in the next few years, and over the next decade, the PLAN will likely advance development of new guided-missile nuclear attack submarines to improve its anti-surface capabilities as well as its land-attack options. Expanded undersea capabilities would enhance China's ability to defeat an adversary at sea, and to decimate the shipping and infrastructure crucial to waging war.

One concern for the US is that China is enhancing the power of its submarine force through espionage and other malign behavior.

While the US maintains a "significant asymmetric advantage in undersea warfare," China is "making progress," Adm. Philip Davidson, the new head of Indo-Pacific Command, told senators in April, adding that Beijing "has identified undersea warfare as a priority, both for increasing their own capabilities as well as challenging ours."

A Chinese submarine attends an offshore blockade exercise Zha Chunming/Xinhua/Associated Press

Davidson warned that China is "stealing technology in just about every domain and trying to use it to their advantage." In June, The Washington Post broke news that Chinese government hackers stole a boatload of submarine warfare secrets from a US Navy contractor.

"They have new submarines on both the ballistic missile side and the attack submarine side, and they're achieving numbers in the build of those submarines as well," the admiral told Congress. "They're also pursuing other technologies to give them better insights into our operations in the undersea domain."

Richard, who commands what his predecessor called "the greatest submarine force the world has ever known," faces a difficult challenge, but his service record suggests he's up to the challenge. The Alabama native previously commanded the USS Parche, one of the US Navy's most decorated warfighting vessels.