President Donald Trump, Vice President Mike Pence and other political leaders on Wednesday denounced the suspicious packages sent to 2016 Democratic presidential nominee Hillary Clinton, President Barack Obama and CNN's New York bureau, among other locations.
The White House called the attempted attacks "despicable."
"The United States Secret Service and other law enforcement agencies are investigating and will take all appropriate actions to protect anyone threatened by these cowards," White House press secretary Sarah Sanders said in a statement.
Responding to a tweet from Pence, who said the administration condemned the "despicable" actions and that "those responsible will be brought to justice," Trump said on Twitter, "I agree wholeheartedly!"
"This clearly is an act of terror attempting to undermine our free press and leaders of this country through acts of violence," New York Mayor Bill de Blasio said at an afternoon news conference about the package sent to CNN's office at the Time Warner Center in New York City.
New York Gov. Andrew Cuomo echoed the mayor, saying, "Terrorism only works if you let it work. We will not allow these terrorist thugs to change the way we live our lives."
National Counterterrorism Center spokesperson Maura Beard tells CNN that officials there have not yet concluded that there is a link to foreign terrorism with the suspicious packages.
The Secret Service said Wednesday it intercepted two "suspicious packages" addressed to Obama and Clinton it discovered during "routine mail screening procedures" earlier this week.
Pence said in his tweet he was "grateful for swift response" of the Secret Service, FBI and local law enforcement, who are investigating whether the packages intended for Obama and Clinton are connected to the package targeting major Democratic donor George Soros earlier this week.
"Let me be clear, we condemn these attempted acts of violence in the strongest possible terms," Pence said later, speaking at a campaign event in Pennsylvania.
The President's family -- first lady Melania Trump, the President's daughter and adviser Ivanka Trump and sons Donald Trump Jr. and Eric Trump -- condemned the threats.
"These terrorizing acts are despicable, and anyone responsible will be held accountable to the fullest extent of the law," Sanders said in a statement.
House Speaker Paul Ryan echoed Sanders' statement, saying that "those behind such reprehensible acts must be brought to justice."
"We cannot tolerate any attempt to terrorize public figures," the Wisconsin Republican tweeted.
House Majority Whip Steve Scalise, who was seriously wounded from a gunshot last summer, said the attempted attacks "are beyond criminal, they are acts of pure terror."
"Violence and terror have no place in our politics or anywhere else in our society," the Louisiana Republican posted on Twitter. "I have experienced first-hand the effects of political violence, and am committed to using my voice to speak out against it wherever I can."
Scalise added that this "cannot become the new normal."
Republican Sen. Jeff Flake of Arizona, who was on the baseball field with Scalise during the 2017 shooting attack, warned that we are in "terrible times" and called for Americans to "tone down the rhetoric" on "both sides" of the aisle.
"We've got to tone it down. We've got to see people as opponents, but not enemies," Flake told CNN's Maria Santana outside the evacuated Time Warner Center on Wednesday morning.
Senate Majority Leader Mitch McConnell of Kentucky too condemned the incidents in a statement from his office saying, "As we continue to learn more, Americans are united in gratitude for the first responders — the Secret Service, the Postal Service, and other law enforcement — who protect our leaders and public figures from such unconscionable acts."
Asked whether discourse has contributed to increasing threats like the suspicious packages, Republican Sen. Orrin Hatch told CNN that there are "a lot of things" that have contributed to the rising political rhetoric, saying that "our society has become fairly complex."
The Utah Republican suggested that people "ought to moderate their positions, both sides."
Asked if that pertained to the President, who has labeled Democrats and media the enemy, Hatch said, "I don't see anything really wrong with the President. I think that he's in a tough position. He's getting attacked on all sides, so he ought to be able to express himself."
Republican Sen. Marco Rubio of Florida was forceful in his response, saying that an "attack on an American who happens to be a Democrat, Republican or independent is an attack on America."
"Some already giving in to temptation to react to this terror attack by either assigning blame for or rationalizing it," Rubio wrote on Twitter. "No sane or well intentioned person, no matter how partisan, would do this. It's either the work of a demented person or terror aimed at further dividing America."
Democrats also called out the attempted violence.
"Once again, we are reminded of the heroism of America's first responders as they work to counter these attempted attacks," House Minority Leader Nancy Pelosi of California said.
She added, "We will not allow them to diminish our commitment to building a brighter future for communities across America."
On Twitter, Democratic Sens. Tim Kaine of Virginia, Clinton's running mate in 2016, and Elizabeth Warren of Massachusetts said the threats have "no place in our free and lawful society" and "no place in our democracy."