Independent US Senator Angus King has announced that he would vote in favor of the conclusion of nuclear negotiations between Iran and the world powers because other options are “unrealistic” or “dangerous.”

"I have never faced a more difficult decision than a vote on the Iran nuclear decision," the Maine senator said on Wednesday.

"The current alternatives, if this agreement is rejected, are either unrealistic or downright dangerous. And so, based upon what we know now, I intend to vote in favor of the agreement," he added.

In September, Congress will vote on the Joint Comprehensive Plan of Action (JCPOA) reached between Iran and the P5+1 group -- the United States, Britain, France, China, Russia and Germany –  in the Austrian capital of Vienna on July 14.

According to the accord, Iran will be recognized by the United Nations as a nuclear power and will continue its uranium enrichment program.

Iran sanctions are set to be removed in exchange for some limitations on the country’s nuclear energy program.

Democratic Senators Tim Kaine, Bill Nelson, Barbara Boxer, Chris Murphy and Patrick Leahy have so far supported the conclusion of the nuclear talks.

Senator King also noted that "no negotiated agreement is perfect, and it's easy to pick apart whatever agreement is before you."

On Wednesday, President Barack Obama once again defended his administration’s efforts to conclude the nuclear talks.

Obama said “those who call for a 'better deal' are ignorant of the Iranian society or just not being straight with the American people.”

He urged Congress not to block the agreement during a speech at American University.

“By killing this deal, Congress would not only pave Iran's pathway to a bomb, it would accelerate it,” he said.