WASHINGTON — President Barack Obama weighed into two international struggles Tuesday, vowing to come down like “a ton of bricks” on firms that violate sanctions against Iran and acknowledging that Syrian peace talks are far from reaching their goal.

“There’s enormous frustration here,” Obama said of the Syrian peace talks.

Obama made the remarks at a joint news conference with French President Francois Hollande, a key partner in both the Syrian and Iranian efforts.

The United States and France are among the countries that signed an interim nuclear agreement with Tehran. The agreement halts progress on the Islamic republic’s nuclear program in exchange for easing international sanctions. Talks on a final deal begin next week in Vienna, Austria.

Speaking on companies doing business with Iran in violation of sanctions still in place, Obama said, “We will come down on them like a ton of bricks” if they don’t hold up their end.

The Obama administration has objected to the interest French businesses have shown in Iran since the sanctions were eased. More than 100 French executives visited Tehran last week, a trip Secretary of State John Kerry told his counterparts in Paris was “not helpful.”

Hollande said he told the French businessmen that sanctions remain in effect and no commercial agreements can be signed without a long-term, comprehensive nuclear deal. But he said he’s not president of the French employer’s union and companies make their own travel decisions.

The United States and France have been working to end the violent civil war in Syria, a former French colony. But peace talks between the Syrian government and opposition forces have gained no traction.

An agreement to strip Syria of its chemical weapons stockpiles is being carried out. But there are concerns on both sides of the Atlantic that Syria is stalling on its obligations.

When Obama threatened a military strike against Syria following a chemical weapons attack there last year, France was the only European ally ready to join that effort.

The United State and France have rebuilt a relationship that “would have been unimaginable even a decade ago,” after President George W. Bush launched an unpopular war against Iraq.

Obama says the transformation stands as a testament to how Washington and Paris have worked to transform their alliance, as the two leaders worked to project a renewed relationship between their countries after hitting a low point more than a decade ago over France’s staunch opposition to the American-led war in Iraq.

There has been some tension between the U.S. and its allies in Europe and elsewhere following revelations that their leaders had been subject to spying from the National Security Agency.

Obama said there is no country with which the United States has “a no-spy agreement.” But he says the United States endeavors to protect privacy rights as it collects foreign intelligence.

Obama also announced that he’s accepted Hollande’s invitation to travel to France for the June 6 ceremony marking the 70th anniversary of the D-Day invasion of Normandy.

On a domestic issue, Obama said he’s giving mid-size businesses more time to comply with his health care law because they are trying to get right with the law. “The purpose of the law is not to punish them,” Obama said, but to make sure they are providing insurance or helping pay for their employees to obtain it.

The Obama administration on Monday delayed a requirement that medium-to-larger firms provide health care for their workers or face fines. The administration said companies with 50 to 99 employees will have an additional year to comply with the coverage requirement, until January 1, 2016.

Republicans trying to win control of the Senate in the November elections are making the health care law their top issue, criticizing it as a job-costing burden on businesses and individuals.

The remarks came at a news conference in the midst of an official state visit, held as Hollande is facing romantic upheaval that resulted in his showing up stag to the White House. The 59-year-old ended his relationship last month with girlfriend and French first lady Valerie Trierweiler after it was revealed that he was having an affair with an actress.

The White House has carefully avoided any mention of Hollande’s personal drama and has moved forward with a grand welcome reserved only for America’s closest allies.

On a cold February morning, Obama, first lady Michelle Obama and a military honor guard welcomed Hollande as he arrived on the South Lawn of the White House. The two leaders shook hands before a cheering crowd, many waving American and French flags, and greeted two American military veterans who served in France during World War II.

Following the arrival ceremony, Obama and Hollande held a private meeting in the Oval Office before appearing before the press in the East Room. The Obamas planned to fete Hollande at a grand state dinner Tuesday night attended by more than 300 dignitaries and celebrities.

Follow Julie Pace at http://twitter.com/jpaceDC