President Trump said Wednesday that the bill he signed into law that tightens sanctions against Russia, Iran and North Korea is "significantly flawed" and even includes some "unconstitutional provisions."

"In its haste to pass this legislation, the Congress included a number of clearly unconstitutional provisions," Trump said in a formal statement after signing the bill, the Countering America's Adversaries Through Sanctions Act.

In a separate, less formal statement, Trump said the bill "encroaches on the executive branch's authority to negotiate," and said he could do a better job than Congress negotiating these issues.

"I built a truly great company worth many billions of dollars," he said. "That is a big part of the reason I was elected. As president, I can make far better deals with foreign countries than Congress."

But Trump said he was signing the bill "for the sake of national unity."

"It represents the will of the American people to see Russia take steps to improve relations with the United States," he said. "We hope there will be cooperation between our two countries on major global issues so that these sanctions will no longer be necessary."

The statements are the first detailed look at the Trump administration's view of the bill, and an early look at a signing statement from Trump on a bill with which he does not fully agree. Signing statements often accompany legislation that is signed by the president, and often provides a glimpse into how an administration will implement the legislation at hand.

In his more formal statement, Trump said one example of a problem with the bill is language that he said would "displace the president's exclusive constitutional authority to recognize foreign governments." He said that language conflicts with a Supreme Court ruling.

The language in question is sections 253 and 257 of the bill. The first says the U.S. government does not recognize territorial changes put into place through force, including invasions and occupations of Crimea and Eastern Ukraine.

The second section says it's U.S. policy to "never recognize the illegal annexation of Crimea."

Trump also criticized section 216 of the bill, which gives Congress the ability to change the law "outside the constitutionally required process," because it creates a review period that "precludes the president from taking certain actions."

That section gives Congress the right to review a decision by Trump to waive sanctions against Russia.

"I nevertheless expect to honor the bill's extended waiting periods to ensure that the Congress will have a full opportunity to avail itself of the bill's review procedures," he said.

Trump listed several other sections of the bill that he said would require him to deny certain people entry into the United States, and have no exception for his authority to receive ambassadors.

In his formal statement, Trump would "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."