Top national security officials made a rare appearance in the White House briefing room Thursday to warn that Russia continues to target the U.S. election system and vow that the Trump administration has made combating interference a priority ahead of the midterms in November.

Although the officials, including Director of National Intelligence Daniel Coats and national security adviser John Bolton, did not offer new details about any attacks or announce new policies, their show of unity just steps from the Oval Office appeared aimed at easing public concerns about President Trump’s public skepticism of Russia’s intentions.

“In regards to Russian involvement in the midterm elections, we continue to see a pervasive messaging campaign by Russia to try to weaken and divide the United States,” Coats told the White House press corps in the live-televised briefing. Homeland Security Secretary Kirstjen Nielsen, FBI Director Christopher A. Wray and National Security Agency Director Paul Nakasone also attended.

Coats added that other entities also have the capability to wreak havoc on the election and could be considering an influence campaign.

“We’re here to tell the American people that we acknowledged the threat, it is real, it is continuing, and we’re doing everything we can to have an election the American people can have trust in,” he said.

Lawmakers and independent analysts say that U.S. voting systems are more secure against hackers thanks to action at the federal and state levels — and that the Russians have not targeted those systems to the degree they did in 2016.

But Russian efforts to manipulate U.S. voters through misleading social media postings are likely to have grown more sophisticated and harder to detect, and there is not a sufficiently strong government strategy to combat information warfare against the United States, outside experts warn.

“Glad to see the White House finally do something about election security — even if it’s only a press conference,” Sen. Mark R. Warner of Virginia, the top Democrat on the Senate Intelligence Committee, said in a tweet. “Now if only it was actually backed up by anything the President has said or done on Russia.”

Asked whether Trump should speak out forcefully against Russian interference, Sen. Marco Rubio (R-Fla.) told reporters: “It would be great if the president said it, but what’s even better is the administration is doing something about it.”

Thursday’s news conference was the first time that the heads of the intelligence and law enforcement agencies with a role in preventing election interference have appeared together to address the threat. Their decision to do so from inside the White House, and to entertain questions from reporters, suggested that Trump’s aides remain concerned about the public’s confidence in how thoroughly the administration is preparing to safeguard the integrity of the elections.

Their joint appearance follows a meeting last week of the National Security Council on election security, the first Trump has led on the matter, which lasted less than an hour and produced no new orders on how to counter or deter the interference.

White House aides have insisted that Trump takes the threats of outside interference in the election seriously, even as he has railed against the ongoing investigation from special counsel Robert S. Mueller III into Russia’s actions in the 2016 presidential election as a “witch hunt.”

The president declined to publicly condemn Russian President Vladi­mir Putin during a summit in Helsinki last month, drawing intense public criticism from lawmakers in both parties.

Bolton emphasized Thursday that Trump raised the issue with Putin in private.

“President Trump has not and will not tolerate interference in America’s system of representative government,” Bolton said in a letter to Senate Democrats outlining administration actions since Trump took office, including economic sanctions on Russian entities and the expulsion of Russian diplomats from the United States.

The Democrats who received the letter later complained Bolton did not address their questions about implementing sanctions and increased election security funding.

“We implore the administration to take this very real and imminent threat to our elections and our democracy more seriously,” Sens. Charles E. Schumer (D-N.Y.), Richard J. Durbin (D-Ill.), Dianne Feinstein (D-Clif.), Amy Klobuchar (D-Minn.) and Chris Van Hollen (D-Md.) said in a statement.

The agency leaders announced no new policies and in some instances did not directly answer questions about what particular guidance or orders they were given to counteract Russian moves.

The officials described Russian actions observed to date as significant but not as multifaceted as those that intelligence agencies saw during the 2016 campaign.

“We are not yet seeing the same kinds of efforts to specifically target election infrastructure” as in 2016, Wray said, referring to Russian penetration of voter rolls and other efforts to attack the machinery that collects and tabulates vote counts.

“What we are seeing are the malign influence operations,” he said, which has played out in propaganda efforts on social media that Wray called “information warfare.”

Coats said Russian activity in preparation for the midterms “is not the kind of robust campaign” that was undertaken two years ago.

Nakasone, who is also the newly installed commander of U.S. Cyber Command, which has the authority to attack and disable foreign computer networks, was asked what orders he had been given to counteract Russian interference. Nakasone did not answer that question directly. “We’re not going to accept meddling in the elections,” he said.

Hours earlier, a bipartisan group of senators unveiled legislation that would impose aggressive new sanctions on Russia. The move represents the latest attempt by lawmakers to push congressional leaders to intensify punitive measures against would-be election hackers and symbolizes their growing frustration with the White House, which has sent mixed messages on Russia’s attempts to manipulate the American electorate and so far has declined to fully implement sanctions already available to the administration.

David Nakamura, Karoun Demirjian, Erica Werner, Ellen Nakashima and Craig Timberg contributed to this report.