Donald Trump will postpone the announcement of his vice presidential pick due to the apparent terror attack in Nice, France. | AP Photo Trump postpones VP announcement, citing 'horrible attack' in Nice, France The delay would 'absolutely not' have an impact on his final choice, he said.

Donald Trump has postponed the announcement of his vice presidential pick, citing an apparent terrorist attack in Nice, France, that killed dozens.

The sudden delay of the unveiling his running mate, announced via Twitter on Thursday evening, added a dramatic element of uncertainty to an unusually public selection process that is said to have culminated with the choice of Indiana Gov. Mike Pence. Even as an ABC camera crew filmed Pence walking into a Manhattan hotel, Trump immediately followed up his tweet by telling Fox News host Greta van Susteren that he had yet to make a "final, final decision."


The deadly attack in Nice — in which an individual drove a truck through a crowd celebrating the French Bastille Day holiday, reportedly killing at least 70 people and injuring more than 100 — promises to refocus the presidential race on national security, as Trump signaled in a second interview with Fox News' Bill O'Reilly.

"This is war," Trump told his host, vowing that if elected as president, he would call on Congress to declare war against the Islamic State, or ISIL. "We're living in a different world.”

Trump said the delay in announcing his vice presidential pick would "absolutely not" have an impact on his final choice as it would be “totally inappropriate." His campaign said only that "additional details" would follow regarding the timing of the announcement.

Trump's likely presidential rival Hillary Clinton later dialed into O'Reilly's show as well, urging Americans to "stand strongly" with France and calling for a strengthening of U.S. alliances, including NATO.

"We've got to do more to understand that this is a war against these terrorist groups," Clinton said. "We have to be smart in how we wage it. ... We have to be determined that we will win it."

Pence also condemned the attack, calling it "a horrific reminder of the threat facing Western civilization" and expressing solidarity with the French people. His possible Democratic counterpart, Virginia Sen. Tim Kaine, tweeted, "Deepest condolences to #NiceFrance. Joining the rest of the world to #PrayForNice at this difficult time."

Trump has made aggressive rhetoric on terrorism a centerpiece of his campaign, calling for an indefinite ban on Muslim entry into the United States and excoriating President Barack Obama and Clinton for their “weak” policies on Islamic extremism.

Indeed, Trump criticized Obama immediately after the Nice attack, saying the president wasn't doing "anything" about terrorism.

"We’re weakly led and ineffective,” he told van Susteren in his first Fox News interview of the evening. “The first thing [Obama] should do if it is and it may not be … it’s probably, possibly, but if it is indeed radical Islam, it’s about time that he would say so ... Let’s see who did it and what it’s all about.”

Trump then returned to the topic of immigration and refugees from the Middle East. “We can’t let these people pour into our country. We’re allowing thousands of people and we don’t know who they are,” he said.

The swift effort to score political points after a terrorist attack fits a pattern for Trump, who has sought repeatedly to blame Obama and Clinton for the rise of ISIL, also known as ISIS.

“Crooked Hillary will NEVER be able to handle the complexities and danger of ISIS — it will just go on forever. We need change!” he tweeted after a recent spate of attacks in Bangladesh and Iraq.

In June, after an Afghan-American man killed 49 people at an Orlando, Florida, nightclub, Trump demanded that the president step down because he “disgracefully refused to even say the words 'Radical Islam.'” And he urged Clinton to drop out of the 2016 race if she “still cannot say the two words.”

In December, following a mass shooting in San Bernardino, California, Trump told CNN that terrorist attacks were good for his standing in the Republican primary.

"Whenever there's a tragedy, everything goes up, my numbers go way up because we have no strength in this country," he said. "We have weak, sad politicians."

Trump was widely criticized for his initial reaction to the Orlando massacre, in which he tweeted: “Appreciate the congrats for being right on radical Islamic terrorism, I don’t want congrats, I want toughness & vigilance. We must be smart!”

He lashed out at Clinton in a national security-focused speech the next day, accusing her of supporting “the policies that bring the threat of Radical Islam into America, and allow it to grow overseas” and doubling down on his Muslim ban.

Recent polls, however, have found voters largely siding with Clinton’s approach. A Washington Post/ABC survey found that more Americans trust the former secretary of state to handle terrorism than they do Trump, 50 percent to 39 percent.

Obama on Thursday evening offered condolences following the Bastille Day attack, saying the United States will offer any investigatory resources that are needed.

“On behalf of the American people, I condemn in the strongest terms what appears to be a horrific terrorist attack in Nice, France, which killed and wounded dozens of innocent civilians,” the president said in a statement. “We stand in solidarity and partnership with France, our oldest ally, as they respond to and recover from this attack.”

Shane Goldmacher and Kristen East contributed to this report.