President Donald Trump says Iran has not lived up to its part of the deal, and "America will not be held hostage to nuclear blackmail." USA TODAY
WASHINGTON — President Trump said Tuesday that the United States will withdraw from the landmark Iran nuclear agreement and re-impose sanctions on Tehran, a decision that angered allies who fear the prospect of a nuclear arms race in the heart of the Middle East.
 Declaring that "the decaying and the rotten structure" of the 2015 agreement does not block Iran from developing nuclear weapons, Trump said during a speech at the White House that "the Iran deal is defective at its core."
The decision drew criticism from Trump predecessor Barack Obama, who argued in a Facebook post that the deal is working and withdrawing from it is a serious mistake.
"The United States could eventually be left with a losing choice between a nuclear-armed Iran or another war in the Middle East," Obama said.
While European leaders said they would try to maintain the agreement with or without the United States, Iran's president said there is only a "short time" for renegotiations — otherwise his country could speed the process of enriching uranium, a component of weapons making.
“I have ordered Iran’s atomic organization that whenever it is needed, we will start enriching uranium more than before," Iran President Hassan Rouhani said on state television, adding that could start "in the next weeks."
Back in Washington, Trump also announced that Secretary of State Mike Pompeo is again traveling to North Korea to meet with Kim Jong Un to set up a meeting with Trump about Kim's nuclear programs.
Abrogating the Iran nuclear deal should not affect the prospects of a new agreement with North Korea to ends its weapons programs, Trump said, though some analysts questioned that declaration.  "We'll see how it all works out," Trump said. "Maybe it will, maybe it won't."
French President Emmanuel Macron, German Chancellor Angela Merkel and British Prime Minister Theresa May — all of whom urged Trump to stay in the Iran agreement — issued a joint statement expressing "regret and concern" over the decision.