US President Donald Trump Wednesday termed "abhorrent" the sending of "suspicious packages" to former US President Barack Obama, 2016 Democratic presidential nominee Hillary Clinton and the CNN, asserting that threats of political violence have no place in America.

Explosives were also found in package sent to the US news network CNN, after which Time Warner building in New York City, where the CNN bureau is located, was evacuated, the US Secret Service said.

"In these times we have to unify, we have to come together and send one very clear, strong, unmistakable message that acts or threats of political violence of any kind have no place in the United States of America," Trump said.

"This egregious conduct is abhorrent to everything we hold dear and sacred as Americans," he said.

He said his administration will spare "no resources or expense in this effort" to investigate who sent the packages.

"A major federal investigation is under way. This egregious conduct is abhorrent to everything we hold dear and sacred. We're extremely angry, upset, unhappy about what we witnessed this morning and we will get to the bottom of it," he said.

Without takes names of the top democrats - Obama and Clinton - and the news network CNN, Trump referred to explosives devices as "suspicious packages".

"The safety of the American people is my highest and absolute priority," Trump said.

"The full weight of our government is being deployed to conduct this investigation and bring those responsible for these despicable acts to justice," he said.

First Lady Melania Trump also condemned the "cowardly attacks".

"We can not tolerate those cowardly attacks and I strongly condemn all who choose violence," she said.

"I'm grateful to the Secret Service as well as to the local and federal law enforcement for all they do on a daily basis to keep us safe and encourage people across the country to choose kindness over hatred," she added.

The comments were Trump's most extensive since the threats were reported Wednesday morning.

He previously offered a tweet saying he "wholeheartedly" agreed with Vice President Pence's condemnation of the threats.

US Capitol Police are investigating a suspicious package addressed to Democratic Congressman Maxine Waters, multiple news outlets said.

Trump has singled out each individual for criticism since taking office, and he regularly derides CNN as "fake news.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)