WASHINGTON -- During two separate ceremonies on Friday, the Army family and the secretary of defense officially welcomed Secretary of the Army Dr. Mark T. Esper back into the service that raised him.As the newly appointed 23rd secretary of the Army, Esper will be key to the Army's future, said Secretary of Defense James N. Mattis during a swearing-in ceremony at the Pentagon.As international security continues to be a growing concern, Esper -- a West Point graduate and a retired Army lieutenant colonel with combat experience -- will need to "hit the ground running," Mattis said.The defense secretary said he believes Esper will lead an Army that contributes to DOD's three lines of effort: strengthening alliances, reforming business practices, and building lethality."What we have here is someone that we are confident will take the Army forward, that has the right value system [and who] understands that if something is not contributing to lethality, it's going to the dustbin of history," Mattis said.Esper brings with him a wealth of understanding from his time as an Army officer, in the defense industry and on Capitol Hill, Mattis said."This Army has been tested and withstood the strain, but it stood because we have patriotic young people that have put their lives on the line," Mattis said. "I know you are going to keep us feared by our adversaries and reassure our allies. They know when [the Army] shows up they will fight harder alongside us."When the U.S. Army comes, what you're saying is America is putting itself on the line," Mattis said. "That is the bottom line."Esper said he appreciates the direction and support that Mattis gives to each of the five services, and that he couldn't be more inspired to work under the defense secretary's leadership. He also said he is excited to work alongside the leadership that already stands inside the Army."I could not have picked finer Army leadership to serve alongside," Esper said. "And I can't say enough about the virtue of our Soldiers, and their resiliency and willingness to take on the tough tasks that lie ahead."ARRIVALSince coming aboard the Army Nov. 20, Esper has traveled to meet with Soldiers stationed both inside the United States and abroad. He said he's been impressed by what he has seen."In my first 30 days, I have been able to watch the 1st Calvary Division train at Fort Irwin. I've met with the global response force at Fort Bragg, [North Carolina] preparing for a no-notice deployment. And I visited with our troops in combat, in Afghanistan," Esper said during his arrival ceremony at Joint Base Myer-Henderson Hall, Virginia, Friday afternoon."Soldiers are the Army's greatest asset. Their welfare and readiness will always be my top priority," Esper said.Before a large crowd of Soldiers, veterans, families, congressional members, foreign dignitaries and defense industry professionals, Chief of Staff of the Army Gen. Mark A. Milley spoke highly of his new boss."[Esper] has a spine of titanium [and] steel that is not going to bend to the temporary dramas of the day in D.C.," Milley said. "He has the Army's static line like a good jumpmaster. He will not waver. He will never fail to do the right thing for our nation, our troops, or our Army, regardless of the consequences to himself."BUILDING THE FUTURE FORCEAt the official arrival ceremony, Esper discussed his priorities for the Army, which include taking care of people, remaining focused on the Army's values, readiness, modernization, and reform."My first priority is and will remain readiness, ensuring that the total force -- active, Guard and Reserve -- are prepared to deploy, fight and win across the spectrum of conflict," Esper said.Currently, the Army is engaged in over 140 countries around the world. However, fiscal pressures and a lack of steady budget continue to impact the Army's current readiness and affect future operations, Esper said."We are now challenged to address the rise of aggressive near-peer adversaries in Asia and Europe, while our Soldiers continue to fight terrorist groups abroad and reassure our allies around the globe," Esper said."We must continue to build strong alliances and partnerships around the world [with] countries that train together [and] fight well together. And those that fight well together are most likely to win together."Through 2017, Soldiers took the fight to the Islamic State of Iraq and Syria, provided advice and assist support to Afghanistan and other nations, trained with allies and partners in European countries, and provided assistance to citizens recovering from natural disasters."Our job is to be ready -- to be ready for combat," Milley said. "To deter war, but to fight and win if deterrence and diplomacy fail. That is a solemn task for this nation. We are and will remain ready to engage the intense, bloody, unforgiving crucible of ground combat against any foe anytime and anywhere."Esper also identified the need to become better stewards of Army resources, all while modernizing current and future capabilities."This means growing the force while maintaining quality. Reshaping it to be more robust and successful in all domains, and modernizing it with the best weapons and equipment available to guarantee clear overmatch," Esper said.Consequently, for modernization to be successful, improvements need to be made to the current acquisition process, Esper said."This includes improving how requirements are set, empowering acquisition personnel to be successful, ensuring accountability, prototyping, and demonstrating systems early, and involving the private sector much more," Esper said. "We must provide our Soldiers the tools they need to fight and win when they need it. I am confident that the new Futures Command we're designing will do just that."