America's top intelligence officials on Tuesday appeared to challenge some of President Donald Trump's most prominent claims about global national security issues, warning lawmakers that ISIS is still a serious threat to U.S. interests around the world, acknowledging that Iran has -- at least temporarily -- abandoned its efforts to build nuclear weapons, and insisting that North Korea is "unlikely to give up" its own nuclear arsenal.

The testimony to the Senate Intelligence Committee coincided with the release of the U.S. intelligence community's latest "worldwide threat assessment," which noted that even "some U.S. allies and partners are seeking greater independence from Washington in response to their perceptions of changing US policies on security and trade."

"In many respects, it is a rebuke to the political rhetoric from the administration," John Cohen, a senior Homeland Security official focusing on threat-related intelligence under the Obama administration, and an ABC News contributor, said. "[It's] striking in some respects."

Last year, Trump removed the United States from the international deal reached with Iran during the Obama administration, claiming the deal would only provide a cloak for Iran to continue its nuclear development. More recently, the Trump administration has touted its operations against ISIS, with Trump himself tweets last month that ISIS had been "defeated" in Syria.

But on Tuesday, the nation's top intelligence official, Director of National Intelligence Dan Coats, told lawmakers that while ISIS is "nearing territorial defeat" in the region, it "is intent on resurging and still commands thousands of fighters in Iraq and Syria." And Coats said that U.S. intelligence agencies "do not believe Iran is currently undertaking the key activities we judge necessary to produce a nuclear device."

"Iranian officials have publicly threatened to push the boundaries of [the international deal's] restrictions if Iran does not gain the tangible financial benefits it expected from the deal," Coats added.

Cohen, the former Homeland Security official, said that "what is striking about this detailed assessment is what it doesn't say."

"The report does not reinforce or support recent claims by the administration of a national security crisis at the southern border," Cohen said.

In his opening remarks, Coats framed "migration flows" as a "challenge" to U.S. interests, saying Mexican authorities are not able to "fully address" drug cartels. He also said "[h]igh crime rates and weak job markets will continue to spur U.S.-bound migrants from El Salvador, Guatemala and Honduras."

Coats told lawmakers his opening remarks were intended "to provide you an overview of the national security threats facing our nation." He was the only one to give opening remarks, as he was speaking on behalf of those seated beside him: CIA Director Gina Haspel, FBI Director Christopher Wray, National Security Agency Director Gen. Paul Nakasone, Defense Intelligence Agency Director Gen. Robert Ashley and National Geospatial-Intelligence Agency Director Robert Cardillo.

"Threats to U.S. national security will expand and diversify in the coming year, driven in part by China and Russia as they respectively compete more intensely with the United States and its traditional allies and partners," the newly-published 2019 Worldwide Threat Assessment warns. "At the same time, some U.S. allies and partners are seeking greater independence from Washington in response to their perceptions of changing US policies on security and trade and are becoming more open to new bilateral and multilateral partnerships."

China dominated much of the discussion, as Coats said China was leveraging economic, military and political muscle to "tout a distinctly Chinese fusion of strong-man autocracy and a form of western style capitalism as a development model and implicit alternative to democratic values and institutions," in pursuit of "global superiority."

The chairman of the Senate panel, GOP Sen. Richard Burr of North Carolina, echoed those sentiments, warning, "The objective of our enemies has not changed -- they want to see the United States weakened, if not destroyed. They want to see us abandon our friends and allies. They want to see us lessen our global presence. They want to see us weak and divided."

The U.S. officials specifically warned about the economic espionage threat they said emanates from China and targets not only the U.S. government but business and academic institutions.

FBI Director Wray said the nation's use of economic espionage was so widespread that most of the FBI field offices had an open investigation linked to China.

"I would say China writ large is the most significant counter-intelligence threat we face," Wray told lawmakers.

Coats said that China's "pursuit of intellectual property, sensitive research and development plans, and U.S. Person data, remains a significant threat to the US government and private sector."

Wray said, however, that he was "encouraged" that the American people, from those in business to academia, are "now sort of waking up" to the understanding of the blurred lines between Chinese firms and the government and threat that that relationship poses. American allies are starting to rethink their economic and business relationships with the Chinese government and Chinese companies, he said.

Meanwhile, the officials said an economically weakened Russia is working to sow discord in Western institutions and to "undermine the post-WII international order," as Coats put it.

The officials said Russia has continued the social media influence campaign that was so prevalent ahead of the 2016 U.S. presidential election.

The NSA's Nakasone indicated that some actions of his agency, which handles much of the intelligence community's cyber work, diminished Russian capabilities ahead of the 2018 midterm elections. But the threat has hardly gone away, the officials said.

"We assess that foreign actors will view the 2020 U.S. elections as an opportunity to advance their interests," Coats said. "We expect them to refine their capabilities and add new tactics as they learn from each other’s experiences and efforts in previous elections."

When questioned by Democratic Sen. Kamala Harris of California, about whether the intelligence community had a single strategy document for combating foreign influence online ahead of the 2020 election, Coats said that one document wouldn't make sense in such a "fluid" environment, but attempted to assure Harris that it was a top priority for the intelligence community.

Rounding out what Coats called the "Big 4" threats, in addition to Russia and China, the officials fielded questions about Iran and North Korea, mostly about their nuclear aspirations.

Despite President Trump's optimism that North Korean leader Kim Jong Un would denuclearize his nation, the threat assessment said North Korea is unlikely to do so, as it views nuclear weapons as vital to the survival of the regime.

Still, the CIA's Haspel said that North Korea had frozen nuclear testing and that ongoing dialogue between North Korean and U.S. official was "positive," something of value to North Korea. Coats told lawmakers that when it comes to North Korea, the U.S. intelligence community was going into the topic with "eyes wide open."

Haspel also testified that Iran was "technically" in compliance with the 2015 nuclear deal, even if the regime appeared to have taken some steps that might better position the nation should it decide to withdraw from the deal. There were ongoing discussions in Tehran about whether it was worth adhering to the accord's requirements, she said.

Echoing the recently released National Intelligence Strategy, the threat assessment also touched on the dangers of emerging technologies like artificial intelligence, 5G networks and deep fakes, and how they could be utilized by adversary nations.

"All four of these states – China, Russia, North Korea, and Iran – are advancing their cyber capabilities, which are relatively low-cost and growing in potency and severity," Coats said. "This includes threatening both minds and machines in an expanding number of ways, such as stealing information, attempting to influence populations, or developing ways to disrupt critical infrastructures."

The threat assessment warned that both China and Russia currently have the ability to hit "localized" sections of American critical infrastructure -- perhaps interrupting a local electrical grid for a few hours or interfering with a natural gas pipeline for days.

In discussing the terrorist organization ISIS, Haspel said that while the group had lost virtually all of its physical territory in Iraq and Syria, the group still commanded thousands of fighters and said it was "still dangerous."

DNI Coats said it was a threat that wasn't going away anytime soon. "While we have defeated the caliphate except for a couple little villages," he said, the U.S. should not "underestimate" the ability of terror groups like ISIS to live on in different places or through their ideology.

"ISIS will continue to be a threat to the United States," he said.

"The composition of the current threats we face is a toxic mix of strategic competitors, regional powers, weak or failed states, and non-state actors using a variety of tools in overt and subtle ways to achieve their goals," Coats said. "The scale and scope of the various threats facing the United States and our immediate interests worldwide is likely to further intensify this year. It is increasingly a challenge to prioritize which threats are of greatest importance. "