U.S. President Donald Trump warned on Sunday that Iran “better be careful,” in response to Iran’s announcement earlier that it intends to exceed its uranium enrichment beyond what is permitted by the 2015 nuclear accord.

“Iran better be careful, because you enrich for one reason, and I won’t tell you what that reason is, but it’s no good. They better be careful,” he told reporters.

Trump added that “Iran’s doing a lot of bad things,” and that it “will never have a nuclear weapon.”

At a news conference, Iranian government spokesman Ali Rabiei said that Iran would go beyond the 3.67 percent uranium enrichment imposed by the Joint Comprehensive Plan of Action, to an amount “based on our needs.”

The move is expected to increase tensions between Iran and the United States, which unilaterally withdrew from the nuclear deal in May 2018, in addition to reimposing sanctions lifted under it alongside enacting new penalties against Tehran.

Israeli Prime Minister Benjamin Netanyahu warned on Sunday that Iran’s uranium enrichment is a “very, very dangerous step.”

“I call on my friends, the heads of France, Britain and Germany,” he said at a weekly cabinet meeting. “You signed this deal and you said that as soon as they take this step, severe sanctions will be imposed—that was the Security Council resolution. Where are you?”

On July 1, Iran said it had broken the 661-pound limit on its low-enriched uranium stockpile, which experts warned could allow for an Iranian nuclear weapon in less than a year.