President Donald Trump said Saturday that his administration was moving forward with additional sanctions on Iran and he would discuss tensions between the U.S. and the Islamic Republic at Camp David with his advisors this weekend. 

"We are moving forward with additional sanctions on Iran," Trump told reporters as he was departing for Camp David.  "They're going on slowly and in some cases pretty rapidly."

Trump's comments come after he called off strikes against the Islamic Republic over concerns that a military response would kill scores of people. 

"We want to be proportionate," Trump told reporters Saturday. 

Longstanding tensions between the U.S. and Iran have reached a boiling point in recent weeks with the two countries nearly coming to blows. 

Iran shot down a U.S. military surveillance drone with a surface-to-air missile, one week after two oil tankers were rocked by explosions in the Gulf of Oman near the Strait of Hormuz, the world's busiest sea lane for oil shipments.

Tehran said the surveillance drone had violated its airspace, while the U.S. claimed the unmanned aircraft was operating in international airspace. Washington has also blamed Iran for the attacks on the two oil tankers, a charge Tehran strongly denies.

"This is not about the straits," Trump said, referring to the Strait of Hormuz. "This is about Iran cannot have a nuclear weapon."

Trump last year pulled out of an international agreement, negotiated by the Obama administration, that limited Iran's nuclear program. His administration has slapped expansive sanctions back on Iran in an attempt to force the Islamic Republic to make greater concessions.