Republican U.S. Senate candidate Mike McFadden seized on escalating concerns over the spread of the Ebola virus Thursday, calling for a temporary ban on travelers to the United States from West Africa.

"We are not remotely prepared to deal with an Ebola outbreak in the United States," McFadden said at a news conference, saying there are just four state-of-the-art contamination centers in the country, each equipped to hold from three to 10 patients. He said the nation must "aggressively make sure that Ebola is not allowed to take hold and take root in the United States."

McFadden said U.S. aid workers should be able to continue to offer medical help but would have to be subject to a 21-day quarantine. He lambasted his Democratic rival, Sen. Al Franken, and President Obama for not doing enough to address the issue.

Franken, who hosted a women's health roundtable Thursday afternoon with Planned Parenthood Action Fund President Cecile Richards, said later he does not oppose a possible travel ban.

"I think we have to consider that and look at how that would work in terms of delivering aid there, what that means in terms of aid workers going there and coming back," Franken said. "I think it's a reasonable thing to be considering. I just want to know what that means for … a large Liberian Minnesota community, for people traveling to visit there. Can they come back? I'd like to see how that works, but I think it definitely should be considered." Minnesota has one of the largest Liberian populations outside of Liberia.

The drumbeat for a travel ban is growing among Washington lawmakers, starting with GOP House Speaker John Boehner, who said Wednesday that the president should "absolutely consider"a temporary travel ban, "along with any other appropriate actions as doubts about the security of our air travel systems grow." Obama so far has rejected such a ban but by Thursday evening said he was open to considering it.

“We are not remotely prepared to deal with an Ebola outbreak in the United States.” Mike McFadden, GOP challenger

Earlier this week, a second nurse who cared for Liberian Thomas Eric Duncan, who died of Ebola last week, herself was diagnosed with the disease. News that one of the nurses was cleared to fly despite showing a low-grade fever was met with criticism from both the candidates. McFadden said Obama had failed to be proactive as the epidemic widens and compared it to what he said was a similar lack of leadership when Islamic State militants beheaded the second of two American hostages last month. McFadden also tore into Franken for what he said was a lack of action.

"They came back and said, 'We don't have a strategy,' " McFadden said. "I have the exact same feeling now, that there is no strategy. The [Centers for Disease Control and Prevention] allowed this nurse to get on a flight. That's not acceptable. Someone needs to take responsibility for this."

Franken deflected McFadden's criticism, saying he has pushed for increased screening at Minneapolis-St. Paul International Airport and led efforts to ensure that Minnesota health care providers have the necessary federal resources to fight the disease, which has already claimed more than 4,500 lives, primarily in west African nations.

Obama issued an order Thursday authorizing the deployment of National Guard troops to Africa to assist aid workers, if needed. McFadden said he would back the measure so long as troops were adequately protected.

Asked his position, Franken said, "I have seen the reports that the president has issued, an executive order giving the Pentagon authority to call up Guard and reserve members as part of the military's mission in West Africa. I will be closely monitoring this situation and will continue to work closely with the Minnesota National Guard, which is second to none."

While the medical crisis widens, the United States remains without a surgeon general because the position requires Senate confirmation and some Republicans oppose Obama's nominee, Dr. Vivek Murthy. McFadden would not say whether he would vote to confirm Murthy, but he said the president has other options.

"The president can just appoint a cabinet member to take responsibility for the role of Ebola. That's the role of the president," McFadden said.

Abby Simons • 651-925-5043