Vice President Mike Pence warned Iran on Monday that the U.S. military is prepared to defend America's interests amid escalated tensions in the Middle East over the Islamic Republic.

"Let me be clear: Iran should not confuse American restraint with a lack of American resolve," Pence said, hours after Tehran claimed it had enriched uranium beyond limits set by a 2015 multilateral nuclear deal.

"We hope for the best, but the United States of America and our military are prepared to protect our interests and protect our personnel and our citizens in the region," he told an annual meeting of a pro-Israel Christian organization.

In late June, the United States was on the verge of launching a military strike against Iran following the downing of an unmanned American drone by the country's paramilitary Islamic Revolutionary Guard Corps.

Speaking at the same meeting, U.S. national security adviser John Bolton also condemned Iran's latest action.

"Tehran's continued pursuit of a nuclear program, including recent increases in uranium stockpiles and enrichment levels, is in direct violation of its commitments under the nuclear deal," Bolton said.

"It's certainly a grave threat to international peace and security," he said.

Pence said Washington will continue to apply maximum pressure on Tehran in concert with the international community, and that President Donald Trump's administration "will never allow Iran to obtain a nuclear weapon."

Pence said the "disastrous" nuclear deal -- struck under former President Barack Obama's administration -- "simply delayed" Tehran's development of a nuclear weapon for about a decade in exchange for giving away "billions of dollars in cash and sanctions relief that Iran has used to fund more terrorist attacks on innocents across the region."

The Trump administration has imposed a series of sanctions on Tehran since the president withdrew the United States from the nuclear deal last year.

Under the deal involving Iran and six powers -- Britain, China, France, Germany, Russia and the United States -- Iran agreed to curb its nuclear activities in exchange for the lifting of economic sanctions.