In this June 13, 2017, file photo. Joint Chiefs Chairman Gen. Joseph Dunford listens on Capitol Hill in Washington. Associated Press/Jacquelyn Martin The Chairman of the Joint Chiefs testified to the Senate Armed Services Committee on Tuesday that China would "probably" pose the greatest threat to the United States by 2025.

In a hearing before the Committee votes to reappoint Gen. Joseph Dunford in his current role as the top military advisor to the president, he addressed the rise of China, Russia's increasing use of electronic and cyber warfare, and worries over threats from North Korea.

"The Russians, Chinese, and others are doing what I describe as conducting competition at a level that falls below conflict," Dunford said. "In my judgment, we need to improve our ability to compete in that space and in the areas specifically ... our electronic warfare and information operations capability."

Although Dunford is expected to easily win support from Congress to remain on the job, he was asked about a variety of issues. Here's what he said in response to a number of senator's questions:

On how the US is faring in Afghanistan:

"I do not believe that we can attain our objectives in Afghanistan unless we materially change the behavior of Pakistan."

Dunford's answer was in relation to the Taliban and Haqqani Network's use of Pakistan as a sanctuary, and its government's lack of ability to combat those groups within the country.

On what's going on in North Korea:

Although the war of words between the United States and North Korea has seemed to reach a fever pitch, Dunford told the commit ee the Pentagon had not "seen a change in the posture of North Korean forces."

We are applying “economic and diplomatic means” on North Korea to denuclearize, he said, although he admitted that Kim Jong-un's nuclear ambitions were a means to assure his regime's survival. When one senator noted the tension stemming from rhetoric between the two nations, Dunford said that the military had been careful not to "exacerbate" the situation with statements about destroying the Kim regime, but he would not comment on "senior political leadership."

North Korean leader Kim Jong Un guides a target-striking contest of the special operation forces of the Korean People's Army (KPA) to occupy islands in this undated picture provided by KCNA in Pyongyang on August 25, 2017. KCNA via Reuters

Senior political leadership — i.e. President Trump — has repeatedly threatened North Korea with military strikes. In his recent speech to the United Nations, he said he would "totally destroy North Korea" in response to military action from Pyongyang.

North Korea threatened to shoot down US bombers in response.

As far as Pyongyang's pursuit of a viable nuclear-tipped intercontinental ballistic missile capable of reaching US shores, Dunford said he agreed with US Strategic Command's assessment that North Korea would likely develop that capable by the end of 2018.

"There are military options available to the president if our economic and diplomatic pressure campaign fails," Dunford said.

On recent ship collisions and accidents that have resulted in the deaths and injuries of US troops:

There have been a number of deadly incidents in recent months involving ship collisions, helicopter crashes, and most recently, a Marine armored vehicle catching on fire at Camp Pendleton.

"I am confident," Dunford said, that fiscal constraints and high operational tempo were behind at least some of those incidents.

When it comes to the Navy, which has had four ship collisions this year, Dunford said the demands on sailors "does exceed the supply." Some sailors work 100 hours per week while underway, according to a recent Government Accountability Office report.

Damage to the USS John McCain following a collision with the Alnic MC merchant vessel. Joshua Fulton/US Navy

Dunford told the committee that he had recently been onboard the USS Barry, which he learned had been out to sea for more than two-thirds of the past year.

"70% of the time underway is an unsustainable rate," he said.

On the fight against ISIS:

Dunford was asked about the fight in and around Raqqa, the Islamic State's self-proclaimed capital. That fight is currently underway, and while the general cautioned against giving timelines, he said that combat operations in the city would likely be complete within the next six months.

"We'll continue to see a reduction in territory," Dunford said. He added, however, that ISIS would not be completely destroyed, and the group would likely continue to carry out terror attacks despite losing its home base.

Other odds and ends:

Dunford said he was "concerned" about a recent Kurdish independence vote, which he said may possibly have some effect on cooperation between Kurds and Iraqi forces that are currently engaged against ISIS.

On transgender soldiers — which are currently in limbo as the Pentagon reviews the issue — Dunford said, "I do," when asked if he believed that trans soldiers have served with honor and valor by Democratic Sen. Kirsten Gillibrand.

He also told Gillibrand that he didn't think "any of us are satisfied" with where the military is in terms of addressing the problem of sexual assault, and committed to working with her on the issue.

Dunford said that he supported lethal military assistance for Ukraine, which was still pending approval from The White House. "Their ability to stop armored vehicles would be essential to them to protect themselves," he said.

The general also said the military was working to support people devastated by the hurricane in Puerto Rico but they were having trouble with damaged ports and air fields. He said Secretary Mattis' guidance was, "What they need they get. Just make it happen.”

Finally, Dunford and the committee exchanged a few book and television recommendations. At the opening of the hearing, Republican Sen. John McCain told Dunford he should be watching the Ken Burns' documentary on the Vietnam War, and later, he was asked whether he had read Lt. Gen. H.R. McMaster's book "Derelection of Duty," about the failures of the Joint Chiefs during the Vietnam War (he had).