It’s official: Congress has handcuffed Donald Trump on Russia.

On Wednesday morning, President Trump grudgingly signed a bill into law that imposes new sanctions on Russia and sharply limits his ability to lift them. Since the bill sailed through Congress with a veto-proof majority, his only options were to sign it or to veto it and then endure the humiliation of seeing Congress — controlled by his own party — override him with ease, as lawmakers in both parties pledged to do.

When he signed the bill, he issued a statement calling the law “significantly flawed” and claiming that it contains “unconstitutional provisions” in its restrictions on presidential authority.

The bill is a major blow to Trump’s agenda to warm relations with Moscow, and demonstrates that even in a time of partisan rancor and near-total legislative dysfunction, both parties can agree that Trump simply can’t be trusted to deal with Russia without their input.

Last week, sanctions legislation targeting Russia soared through the Senate by a margin of 98-2, just days after it coasted through the House of Representatives 419-3.

The bill takes Obama-era sanctions against Russia that are in place under executive orders — that is, directives that only the president has authority to enact and rescind — and officially enshrines them in the law. It also establishes a new congressional review process that would allow Congress to block the White House from taking steps to ease sanctions if it wanted to. And it imposes a fresh batch of sanctions on Russia, Iran, and North Korea.

Trump wanted to keep sanctions under his control as he angles to turn things around in the rapidly souring US-Russian relationship. Moscow despises US sanctions, and their removal would be central to any kind of major reset between the two countries.

But now that’s not happening, and Russia has already made its fury over the legislation plain: On Friday, after the Senate passed the bill, Russia’s Foreign Ministry announced that it was cutting the number of US diplomatic personnel in Russia down to a number that matches the number of Russian diplomatic personnel in the US.

Russia also said that it will seize a dacha, or country house, outside Moscow that US personnel use, as well as a storage facility.

“Any new unilateral actions by the US authorities to reduce the number of our diplomats in the United States will be met with a mirror response," the ministry promised in a statement.

Russia has lost interest in Trump’s outreach

The response is a major setback for Trump’s ambition to turn over a new leaf with Russia, and stands in stark contrast to Moscow’s response to the last time the US took strong actions against it.

Back in December, after President Obama announced a raft of new sanctions against Russia and the expulsion of dozens of Russian diplomats from the US as a penalty for its meddling in the 2016 election, Vladimir Putin refrained from retaliation. No diplomats were ejected from Russia; no compounds were seized. In fact, he went a step further, inviting the children of US diplomats to join Christmas parties in the Kremlin. And there was only one reason he did that: He was optimistic about Trump’s interest in warming ties with Moscow and wanted to give him a chance to reverse Obama’s sanctions.

That window of opportunity appears to have closed, and it’s Trump’s own fault.

The Republican Party has extraordinary strategic discipline. They haven’t been particularly keen on hitting Trump hard with investigations over his inner circle’s ties to Russia during the campaign, but they do realize how politically risky it is for Trump to have free rein to lift sanctions on his own while he’s being investigated.

Many of them also genuinely think that Putin will play Trump for a fool in any deal they strike, and want to make sure he doesn’t give away the US’s biggest bargaining chip without them having a say in it.

Now the big question is what does Trump’s statement of concern about the new law mean? It suggests that when it comes to actually executing future sanctions he could interpret the law in a manner that clashes with Congress’ understanding of it. That could mean more fights over Russia sanctions are in store.