Washington (EFE) -- Department of Homeland Security Secretary Jeh Johnson said Tuesday that there is - at present - no evidence of "specific, credible" terrorist threats similar to the recent terrorist attacks in Belgium which left at least 34 people dead and more than 200 wounded.

"At present, we have no specific, credible intelligence of any plot to conduct similar attacks here in the United States," the U.S. security chief said in a communique. "That said, we remain very focused on the threat posed by lone terrorist actors who may lack direct connection to a foreign terrorist organization; we are concerned that such radicalized individuals or small groups could carry out an attack in the Homeland with little warning."

Johnson said that Washington remains committed to identifying and disrupting the plans of foreign terrorists who could travel to or from the United States. The DHS chief said that his department, along with other law enforcement and intelligence authorities, is undertaking a series of actions to "monitor events in Brussels, work with the authorities there" and continue to increase U.S. security.

The DHS director added that the United States has increased the exchange of information with Belgian and French authorities since the attacks last November in Paris, and it has procedures to "identify and prevent" suspicious individuals from traveling to the United States from Belgium.

In addition, among other things the Transportation Safety Administration has strengthened security at airports in the largest U.S. cities as a precaution. As President Barack Obama did earlier on Tuesday, Johnson expressed his solidarity with the Belgian people and condemned the terrorist attacks.

The secretary also offered U.S. support to Belgian authorities to do everything possible to bring to justice those responsible for the attacks, for which the Islamic State has claimed responsibility.