The top U.S. military official in the Pacific defended the Navy on Tuesday concerning two embarrassing collisions at sea that combined killed 17 sailors, saying that “the fact of the matter is 280-odd other ships weren’t having collisions.”

The comments by Adm. Phil Davidson came during questioning at a Senate Armed Services Committee hearing after he said the Navy’s senior leadership feels “an immense amount of accountability” for disasters involving the USS Fitzgerald and USS John S. McCain. The ships collided with commercial vessels about two months apart in the summer of 2017, with the sailors drowning inside flooded compartments.

Sen. Angus King (I-Maine) asked Davidson, who oversaw the Navy’s investigation of the disasters, about the recent publication of investigative reports by ProPublica in which former senior defense officials said Navy leaders had ignored pleas for help to make sure sailors were appropriately trained and ships were well maintained. The senator appeared to take exception to Davidson’s remarks.

“Airplanes are landing all over America, and just because they aren’t all crashing doesn’t mean they don’t need a high level of maintenance,” King said. “To tell me that isn’t very convincing. I think it had been 40 years since we’ve had collisions of this nature? Are you saying that there were failures that led to these collisions because there were 280 ships that didn’t have collisions? Isn’t that the standard? No collisions?"

King called the collisions “avoidable tragedies” and asked for specific data about the certification of sailors to deploy, maintenance aboard ships, training and staffing levels.

Davidson said that the suggestion that there isn’t transparency about the Navy’s readiness “is appalling” and that he testified before Congress in 2016 about what it took to keep deploying under difficult circumstances. The admiral performed a review that led to 58 recommendations, Davidson said, “and the Navy is moving out on those recommendations” to improve the situation.

The exchange came at a hearing at which Army Gen. Robert B. Abrams, the top commander of U.S. Forces Korea, also appeared. He told committee members that while U.S. officials continue to speak with North Korean officials about eliminating their nuclear weapons program, “little to no verifiable change has occurred in North Korea’s military capabilities.”

Abrams, speaking about two weeks before President Trump is due to meet for a second time with North Korean leader Kim Jong Un, said North Korea had not made any significant changes to the size, scope or timing of its military exercises, and the nation’s military capabilities remain “unchecked.”

“These capabilities continue to hold the United States, the Republic of Korea and our regional allies at risk,” he said. “As such, I believe it is necessary to maintain a postured and ready force to deter any possible aggressive actions.”

Separately, Davidson repeated a frequent warning from Pentagon officials that China continues to erode the U.S. military advantage in the Pacific region. The Pentagon’s financial investments last year helped, he said, but more is necessary in each of the next two budgets, he said.

“I don’t want to give the impression that last year’s budget is necessarily putting us on the track to regain that advantage,” he said.

One new option on the table could be intermediate ballistic missiles. The Trump administration announced this month that it will withdraw from the Intermediate-Range Nuclear Forces Treaty with Russia, allowing the United States to pursue arms that it says China and Russia already are pursing.

Davidson said about 95 percent of the ballistic missiles built by China, which was not a party to the treaty, would violate it. He said a similar capability would make the U.S. military “more viable in any warfare scenario and present a much greater challenge for our adversaries to threaten.”

Davidson, under questioning from Sen. Tom Cotton (R-Ark.), said it will be necessary for those missiles to be mobile on land, meaning they probably would be fired from some sort of vehicle on wheels.

“In this day and age, if it is fixed on the planet, it is dead,” Davidson said. “You don’t even need space assets to support that. The globe has been mapped, and a ballistic missile can find its way there based on its own internal targeting. We would have to have mobility in those systems.”