President Trump signed into law Wednesday legislation that will impose new sanctions on Russia, but he immediately expressed doubts about its constitutionality and criticized Congress for giving itself greater powers to prevent him from rolling back penalties aimed at Moscow.

Trump’s reluctant signing of the bill came nearly a week after it was approved overwhelmingly by bipartisan majorities in the House and the Senate that assured that any veto could be overridden. Trump’s statement, however, raised questions about whether he will enforce all of the law’s provisions.

He called the legislation — which imposes new penalties on Russia, Iran and North Korea — “seriously flawed,” primarily because it restricts his ability to negotiate sanctions concerning Moscow without congressional approval.

“By limiting the Executive’s flexibility, this bill makes it harder for the United States to strike good deals for the American people, and will drive China, Russia, and North Korea much closer together,” Trump said in a statement Wednesday morning. “The Framers of our Constitution put foreign affairs in the hands of the President. This bill will prove the wisdom of that choice.”

Although Trump said he would honor this section of the law despite his qualms, he argued that other parts of the measure are “clearly unconstitutional” and held out the possibility that he would ignore provisions concerning the territorial integrity of Ukraine and the denial of visas to foreign nationals targeted by the legislation.

(Reuters)

“My Administration will give careful and respectful consideration to the preferences expressed by the Congress in these various provisions and will implement them in a manner consistent with the President’s constitutional authority to conduct foreign relations,” he said.

Trump said his problems with the legislation did not mean he opposed its underlying principles.

“I favor tough measures to punish and deter bad behavior by the rogue regimes in Tehran and Pyongyang,” he said. “I also support making clear that America will not tolerate interference in our democratic process, and that we will side with our allies and friends against Russian subversion and destabilization.”

But lawmakers’ solidarity in ­tying Trump’s hands on Russian sanctions reflects a deepening concern about the White House’s posture toward Moscow, which critics have characterized as naive. The new Russia sanctions expand on measures taken by the Obama administration to punish the Kremlin for its alleged efforts to interfere in the 2016 presidential election. But Trump has continued to cast doubt that Russia alone was responsible, and he has called the investigations of the matter by Congress and by a special counsel a “witch hunt.”

[The Debrief: Pence talks tough on Russia while finding his footing abroad]

The administration’s lobbying of lawmakers in public and private to pull back the legislation’s requirement that Congress review any attempt by the president to amend sanctions against Moscow ultimately fell on deaf ears. The measure imposes a 30-day review period to give Congress a chance to vote down any of the president’s proposed changes to these policies before they can be implemented.

Despite Trump’s objections, House Speaker Paul D. Ryan (R-Wis.) praised the new law.

(Russia/Twitter)

“Today, the United States sent a powerful message to our adversaries that they will be held accountable for their actions,” he said in a statement. “These sanctions directly target the destructive and destabilizing activities of Iran, Russia, and North Korea.”

Trump said he signed the legislation despite his reservations for the sake of “national unity,” but in a pointed jab at lawmakers in his own party, he questioned Congress’s ability to negotiate sanctions based on its inability to approve the Republicans’ health-care legislation.

“The bill remains seriously flawed — particularly because it encroaches on the executive branch’s authority to negotiate,” Trump said. “Congress could not even negotiate a health-care bill after seven years of talking.”

Trump’s decision to detail his concerns in a signing statement, asserting which parts of the law he would enforce, follows in a tradition that has grown more common among modern presidents. President George W. Bush frequently used signing statements to say that he could selectively enforce or ignore parts of bills passed by Congress, including to rebuff congressional restrictions on interrogation techniques. Issuing signing statements continued under President Barack Obama.

[Obama’s secret struggle to retaliate against Putin’s election interference]

Constitutional law experts said that with the sanctions bill, Congress rightfully asserted its powers to serve as a check on the executive branch, even on matters of national security.

Michael Glennon of the Fletcher School of Law and Diplomacy said that Trump’s statement was a “gross misreading” of the case

law he cited to bolster his claim that the congressional review ­provision had unconstitutionally robbed him of the power to negotiate.

“That’s obviously a misguided interpretation of his constitutional authority,” he said. “Congress has very broad authority over foreign commerce — it’s explicitly given the power to regulate commerce with foreign nations. It could have, if it desired, imposed those sanctions without giving the president any waiver authority whatsoever.”

Senators who voted for the measure said they were perplexed by the president’s assertion that it is unconstitutional.

“I don’t know what he’s talking about,” said Sen. Tim Kaine (D-Va). “I don’t think that’s going to stand up.”

Senate Foreign Relations Chairman Bob Corker (R-Tenn.) shrugged off Trump’s criticism.

“It doesn’t matter to me what the signing statement says,” he said. “I know there’s been some resistance at the White House on congressional review, but I think it’s a good and important piece of legislation. I had that conversation with the president directly, and I am glad he signed it and that it has become law.”

Russia this week reacted to Congress’s passage of the sanctions bill — as well as the earlier Obama-imposed measures — by announcing that it would order the U.S. Embassy there to reduce its staff by 755 people and seize U.S. diplomatic properties.

[Putin orders cut of 755 personnel at U.S. missions]

Russian Prime Minister Dmitry Medvedev criticized Trump on Wednesday for signing the bill.

“The Trump administration has shown its total weakness by handing over executive power to Congress in the most humiliating way,” he tweeted.

For now, Trump’s desire to improve relations with Russia has hit a major speed bump at the same time Americans are expressing growing support for an adversarial approach toward Moscow, according to a survey released Wednesday by the Chicago Council on Global Affairs.

The poll found that 53 percent support working to limit Russia’s power, compared with 43 percent who favor friendly cooperation and engagement, a sharp reversal from last year, when 58 percent favored cooperative efforts. More than 4 in 10 said Russian influence in U.S. elections represents a “critical threat” to the country.

The survey found mixed support for imposing additional sanctions, with 38 percent saying they should be increased and 41 percent saying they should be kept about the same. Far fewer, 17 percent, said the United States should decrease or eliminate sanctions on Russia, according to the poll of a random sample of 2,020 adults conducted June 27 to July 19.

Trump praised some recent changes made to the legislation that he said would help U.S. companies, including giving the Treasury Department more flexibility when handing out licenses. But he made clear that he thinks Congress should leave negotiating with foreign powers to him.

“I built a truly great company worth many billions of dollars,” Trump said in his statement. “That is a big part of the reason I was elected. As President, I can make far better deals with foreign countries than Congress.”

Scott Clement contributed to this report.