Breaking News Emails

Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

Treasury Secretary Jack Lew underlined the importance of new sanctions announced by the U.S. Monday against Russia, saying that existing sanctions have already begun to put pressure on the country's economy.

"They're sanctions that will get their attention," Lew said in an interview with NBC News' Andrea Mitchell. "They're now just one notch above junk rating... that's because of the sanctions, as well as the conditions of the economy."

As the existing sanctions have taken hold in Russia, capital has fled the country and the stock market is falling. Foreign companies are jittery about investing, shelving plans to expand or pulling back existing operations.

The new sanctions place asset freezes and U.S. visa bans on seven Russian government officials, including two members of President Valdimir Putin's "inner circle." Asset freezes for 17 companies linked to government officials close to Putin were also announced.

But the sanctions refrain from punishing entire sectors of the Russian economy, such as banking or petroleum, something more hawkish critics, both within the Obama administration and without, have called for.

That's necessary, Lew said, to make sure the sanctions didn't harm innocent bystanders.

"Our goal here is obviously not to hurt the Russian people. It's to get them to change their policy," said Lew. That will only happen,he added, if the U.S. continues to apply pressure in concert with European allies.

The administration had been set to implement the latest batch of sanctions against Russia Friday but held off until Monday to give time for a new round of measures from Europe.

So far, however, the sanctions haven't kept pro-Russian militia from wrecking havoc in Eastern Ukraine and Russia has continued to amass troops at the border. Earlier Monday, masked men swung bats into the backs of pro-Ukranian demonstrators in Donetsk.

"Sanctions are doing what sanctions can do," said Lew. "They're affecting the Russian economy. Obviously, we've made clear that we're prepared to take more steps should we need to. But the idea is to go step by step and to show a determination to keep doing more."