President Trump has taken aim at former Democrats Presidential candidate Hillary Clinton, blaming the former secretary of State for North Korea’s nuclear advances after she berated Trump’s debut speech at the U.N. on Tuesday in New York.

In a tweet referring to former President Bill Clinton as well, Trump wrote, “After allowing North Korea to research and build Nukes while Secretary of State (Bill C also), Crooked Hillary now criticizes”.

After allowing North Korea to research and build Nukes while Secretary of State (Bill C also), Crooked Hillary now criticizes.

— Donald J. Trump (@realDonaldTrump) September 20, 2017

Trump’s tweets came after his 2016 general election opponent ripped his U.N. address, calling it “very dark” and dangerous.

Speaking during an appearance on “The Late Show with Stephen Colbert”, Clinton, said, “When you face dangerous situations like what is happening in North Korea, to make it clear, your first approach should always be diplomatic”.