Two top-ranking senators urged President Donald Trump to robustly enforce a law hitting Russia with new financial sanctions that the president reluctantly approved last month.

Sens. Ben Cardin, D-Md., and John McCain, R-Ariz., wrote to Trump late Thursday that he's obligated to demonstrate "from the highest levels that any effort to undermine U.S. sanctions will not be tolerated." The Associated Press obtained a copy of the letter, which hadn't been released publicly.

The Republican-led Congress responded to Moscow's election meddling by passing an expanded sanctions package in July that also aimed to punish Russia for its military aggression in Ukraine and Syria. Trump grudgingly signed the measure into law in early August while complaining that lawmakers had overstepped their constitutional bounds and impeded his ability to negotiate with foreign countries.

Instead of looking for ways to retaliate against Moscow for the election meddling, Trump openly challenged the findings of his own intelligence agencies, which concluded Russia had sought to tip the election in his behalf. And he pursued a warmer relationship with Russian President Vladimir Putin, convinced that Washington and the Kremlin could work together on shared interests, such as counterterrorism and Syria.

The letter from Cardin and McCain, two of the primary sponsors of the sanctions legislation, underscores concerns among lawmakers that Trump doesn't share their desire to rebuke Russia. The bill included provisions backed by Republican and Democrats to handcuff Trump due to worries he may seek to ease the sanctions without first securing concessions from Putin.

Cardin and McCain told Trump ensuring the new sanctions aren't evaded "requires a robust and sustained effort by your administration to engage in good faith implementation to carry out Congress' clear intent, and to remain vigilant against attempts to undermine the existing Russia sanctions regime."

Cardin is the top ranking Democrat on the Foreign Relations Committee and McCain is chairman of the Armed Services Committee.

The senators pointed to Turkey's deal with the Kremlin to buy Russia's most advanced air defense missile system, the S-400, as an example of how the sanctions law may already have been violated. The purchase has stoked concerns that Turkey, a NATO member, is moving away from the alliance.

They said there is a fast-approaching deadline for the Trump administration to publish a set of regulations mandated by the law. Sanctions can be imposed on people doing business with Russian intelligence and defense agencies and the administration is required by Sunday to specify who these individuals are.

U.S. officials said Russia's leading spy agencies, the GRU and FSB, were involved in the election interference. The GRU is Russia's military intelligence agency. The FSB is the main successor to the Soviet-era KGB.

Cardin and McCain are pushing for an expansive view of how the regulations are crafted to ensure Russia can't skirt the penalties "by funneling the arms trade through companies not included." They want a wide range of Russian government institutions as well as public and private companies to be added, such as arms trader Rosoboronexport and Almaz-Antey, a state-controlled missile manufacturer.


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