When asked if he meant his remarks about Putin sarcastically, Trump told reporters, "Absolutely. I think you know that I think you know that."
Trump's remarks echo White House press secretary Sarah Huckabee Sanders' characterization of his comments.
"He was being sarcastic," Sanders said earlier Friday.
Trump's comments to reporters Friday came after a meeting with Secretary of State Rex Tillerson and Ambassador to the United Nations Nikki Haley in Bedminster, New Jersey. Tillerson told reporters Friday that the United States will have a response to Russia over the expelled diplomats by September 1.
Trump, during a prolonged exchange with reporters Thursday, said he was thankful that Russia expelled American diplomats because the United States is "trying to cut down our payroll."
"I want to thank him because we're trying to cut down our payroll and as far as I'm concerned," Trump had said.
He added: "There's no real reason for them to go back. I greatly appreciate the fact that we've been able to cut our payroll of the United States. We're going to save a lot of money."
The remark instantly reverberated in Washington, where foreign policy and national security experts raised questions about Trump's thanking Putin for the provocative move, especially considering the ongoing investigations into Russia's attempts to influence the 2016 election and possible ties between the Trump campaign and operatives tied to the Kremlin.
"I don't think it's becoming of him to act that way," said Rep. Eliot Engel, a New York Democrat. "The President has to understand, he's president now. It's not just a matter of a show on TV, a reality show, where you are hired and fired."
Trump signed a sanctions bill earlier this month that levied new sanctions against Russia, North Korea and Iran, despite raising concerns about the bill's attempt to restricts his ability to ease the sanctions unilaterally.
The measure passed the House and Senate with veto-proof majorities earlier this year, meaning even if Trump had vetoed the measure, he likely would have been overridden by the executive branch.
In response, the Russian Foreign Ministry ordered the United States to cut 755 staffers, the same number Russia has in the United States, by September 1. The Foreign Ministry also said they would suspend the use of a US storage facility in Moscow and a country house outside Moscow.
A National Security Council spokesperson echoed Sanders' statement, telling CNN that the President was being sarcastic and adding that the Trump administration "take(s) seriously Moscow's unwarranted actions against our personnel and diplomatic properties, and we are exploring our response options."
"Let's remember that it was Russia's interference in our election and treatment of our diplomats that began this negative trend in our relationship," said the spokesperson, who declined to be named.
Trump has raised questions about whether Russia was the primary culprit behind the hacking of Democratic institutions during the 2016 election. Though he has acknowledged Russia was likely involved, he has also suggested it could have been other countries and rouge actors.
The latest sanctions and explosions were the latest in an ongoing tit-for-tat between the United States and Russia. President Barack Obama's administration expelled 35 diplomats from the United States in December under sanctions imposed over Russia's messing in the 2016 election.