President Obama delivered an update on how his administration is responding to the Ebola crisis, after a second health-care worker contracted the virus in the U.S. Obama also stressed the importance of the international response to controlling the outbreak in West Africa. (AP)

President Obama abruptly canceled a campaign trip Wednesday to confer with his top security and health advisers in Washington, seeking to assert greater control over efforts to curb the spread of Ebola in the United States.

The president’s decision to scrap his travel schedule to attend to what press secretary Josh Earnest described as “a pretty urgent situation here in this country” laid bare the challenge the White House faces in managing the federal response to the deadly disease. Federal officials are eagerly trying to restore public confidence in the nation’s public health system at a time when its flaws are glaringly evident.

With a second health-care worker diagnosed with Ebola, who had traveled on a flight from Cleveland to Dallas this week with more than 100 people, top administration officials scrambled Wednesday to reassure Americans the threat remains limited.

“I want people to understand that the dangers of you contracting Ebola, the dangers of a serious outbreak are extraordinarily low,” Obama told reporters after meeting for roughly two hours with aides in the Cabinet Room. “But we are taking this very seriously at the highest levels of government.”

But even the small number of domestic cases is producing political fallout. The president’s assurances did little to ease the concerns of many Republican lawmakers, who have spent several weeks questioning whether the administration has done enough to harden the nation’s defenses against an outbreak.

Vulnerabilities in Ebola planning

Sen. Rob Portman (R-Ohio), who noted that the second nurse had traveled from her home state to Dallas on a crowded flight, said the case “demonstrates why our government must be more proactive in the fight to prevent the spread of Ebola.”

“I have been calling on the president to take such proactive measures for weeks and it’s time for the administration to act,” said Portman, who has called for precautions ranging from more extensive screenings at ports of entry to the appointment of a single administration official to oversee the government’s response to the virus.

Some lawmakers called for even more radical measures in the wake of the crisis. Rep. Tom Marino (R-Pa.) demanded the resignation of Centers for Disease Control and Prevention Director Tom Freiden in addition to a travel ban on all nonmilitary and medical passengers traveling to and from Ebola-affected countries in West Africa. At least three senior Republicans, Sens. Lamar Alexander (Tenn.) and John Thune (S.D.) and Rep. Bill Shuster (Pa.), also endorsed the idea of a travel ban Wednesday.

“This Ebola situation is beginning to spiral beyond control,” Marino said, adding that the information federal officials have given to the public recently “has provided a false sense of security to many of our citizens.”

Separately, House Homeland Security Committee Chairman Michael McCaul (R-Tex.) called on the president to reestablish the White House post of biodefense policy adviser, which existed under Presidents Bill Clinton and George W. Bush.

“By eliminating this position, a key security expert was removed from your team,” McCaul wrote.

While Frieden expressed regret that his agency had not done more earlier to prevent the secondary infections of two nurses at Texas Health Presbyterian Hospital Dallas, White House officials gave no indication they were looking to replace him or change the way they were coordinating the overall government response. Obama’s chief homeland security adviser, Lisa Monaco, is overseeing the inter­agency effort, while former U.S. ambassador to India Nancy Powell is coordinating the nation’s diplomatic efforts.

“We have said on a number of occasions that if additional resources or if additional staffing is necessary to augment the response, then we won’t hesitate to consider it,” said Earnest, who used the word “tenacious” five times during his briefing to describe the administration’s response. “But at this point the lines of authority are clear, and the person responsible for coordinating those efforts here at the White House continues to do that work well.”

Obama — who usually resists changing travel plans in the face of foreign or domestic crises — also continued to press other world leaders to do more to combat the spread of the disease in West Africa. Speaking by phone to Japanese Prime Minister Shinzo Abe on Tuesday night and participating in a conference call with the leaders of Britain, France, Germany and Italy on Wednesday, White House officials said, Obama warned that the international response needs to be more robust.

“Probably the single most important thing that we can do to prevent a more serious Ebola outbreak in this country is making sure that we get what is a raging epidemic right now in West Africa under control,” Obama said.

Stephen Morrison, who directs the Center for Strategic and International Studies’ Global Health Policy Center, said that while CDC officials may have been overconfident initially, they were adjusting course and working to restore the public’s trust.

“We’ve been forced to recognize that this is harder to do than we thought initially,” Morrison said, adding that now federal officials “need to raise people’s confidence that there’s a surge capacity that can be turned up on a dime to address an unforeseen situation” in any town across the nation.