U.S. President Donald Trump has described China and Russia as rivals that must be confronted with "unmatched power," and has called on Congress to fix "fundamental flaws" in the landmark nuclear deal between world powers and Iran.

Trump made the remarks on January 30 in his first State of the Union address to a joint session of the U.S. Congress.

The speech dwelt overwhelmingly on domestic U.S. issues, like rebuilding the country's crumbling infrastructure, an opioid epidemic ravaging some regions, and reforming immigration policies.

But Trump also took time to focus on major foreign-policy challenges faced by the United States.

He referred to "rogue regimes, terrorist groups, and rivals like China and Russia that challenge our interests, our economy, and our values."

"In confronting these dangers, we know that weakness is the surest path to conflict, and unmatched power is the surest means of our defense," he said.

"For this reason, I am asking the Congress to end the dangerous defense sequester and fully fund our great military," he said, referring to a budget deal several years ago that sought to rein in defense spending.

He also referenced recent protests against Iran's ruling Islamic clerics that have swept that country.

"When the people of Iran rose up against the crimes of their corrupt dictatorship, I did not stay silent," he said. "America stands with the people of Iran in their courageous struggle for freedom."

He called on Congress to help pass legislation to fix the 2015 nuclear deal that lifted crippling Western economic sanctions against Tehran in exchange for curbs on its nuclear program.

Trump and many Republicans have routinely criticized the deal, which was negotiated by his predecessor, Barack Obama.

But Trump has stopped short of tearing up the deal altogether, a move some analysts feared could lead Iran to move more quickly to develop a nuclear weapon -- something Tehran says it has not done and does not plan to do.

"I am asking the Congress to address the fundamental flaws in the terrible Iran nuclear deal," Trump said.

Trump also said North Korea's "reckless pursuit" of nuclear missiles could very soon threaten the United States.

He said the United States was waging a campaign of "maximum pressure" against North Korea and its nuclear weapons ambitions, and he called Pyongyang a "cruel dictatorship."

Keeping Guantanamo Open

He also announced that he had signed an executive order to keep the high-security U.S. military detention center open at Guantanamo Bay, Cuba.

"In the past, we have foolishly released hundreds of dangerous terrorists, only to meet them again on the battlefield -- including the ISIS leader, al-Baghdadi," Trump said.

Abu Bakr al-Baghdadi was captured in Iraq by U.S. forces and held in a prison near Baghdad. In 2004, however, he was handed over to Iraqi authorities, who released him some time later.

"I just signed an order directing [Defense] Secretary [Jim] Mattis to reexamine our military detention policy and to keep open the detention facilities at Guantanamo Bay," Trump said.

The executive order reversed a decision by Obama to close the facility -- an order that was never fully implemented because of opposition from U.S. lawmakers.

The detention center was initially opened by President George W. Bush after the September 11, 2001, terrorist attacks in order to hold and interrogate suspected enemy combatants.

At its peak in 2003, it held about 680 detainees. More than 500 were released during the Bush administration and 197 during Obama's eight years in office. It now holds 41 detainees.

A Reset For Year 2?

The speech caps a tumultuous first year in the White House for Trump.

Trump and Republican allies succeeded in passing a major tax overhaul, and the U.S. economy has been humming along at a strong clip, with unemployment continuing to drop and stock markets rising to new heights.

But since Trump's inauguration in January 2017, his presidency has been punctuated by an unusual number of high-ranking staff turnovers, interagency disputes, and backbiting conflicts.

His first year in office has also been dogged by criminal and congressional investigations into interactions between Trump associates and Russian officials.

Four associates have been either indicted on, or pleaded guilty to, various charges including lying to FBI investigators. That includes Trump’s first national security adviser, Michael Flynn.

Trump’s approval ratings among Americans have also hovered at record lows for any president one year into a term.

Experts and political observers noted that Trump's speech echoes past State of the Union addresses in its call for unity and bipartisanship and extolling American virtues. But given Trump's penchant for inflammatory rhetoric, they say that spirit was unlikely to persist, particularly since congressional elections will be held in November.

"Every major address like this is an opportunity for reset, but that is unlikely in this case and even more unlikely still given that it's an election year," Lanhee Chen, a former adviser to former Republican Governor Mitt Romney's 2012 presidential campaign, told The New York Times.

"The real problem is that people just do not listen to his words and treat them with the seriousness that they afford other presidents," presidential historian Michael Beschloss was quoted by The Washington Post as saying. "He has been on so many sides of so many issues that even if it is a good speech, people will figure that it is not going to last long."

State of the Union speeches are typically followed by a rebuttal, or response, from the political party whose candidate is not in the White House.

In remarks that were also carried live by many networks, Democratic Representative Joe Kennedy criticized Trump for stoking anxiety and fear among many Americans.

"It would be easy to dismiss this past year as chaos. As partisanship. As politics. But it's far, far bigger than that. This administration isn't just targeting the laws that protect us -- they are targeting the very idea that we are all worthy of protection," he said.

Kennedy is the latest member of one of the most famous U.S. political dynasties to hold political office. He is the grandson of Robert F. Kennedy, the former senator and U.S. attorney general, and grand-nephew of former U.S. President John F. Kennedy.