United States President Barack Obama said Friday that the US and European Union are still prepared to impose sanctions against Russia if the crisis in Ukraine continues to escalate following the signing of a ceasefire agreement.

Speaking in Newport, Wales at the close of a major NATO alliance summit, Pres. Obama expressed skepticism over a pact signed only hours earlier in Minsk during a meeting of representatives from Kiev, Lugansk and Donetsk, and said the US intends to go ahead with new sanctions revealed by the White House on Thursday this week.

“Obviously we are hopeful,” Obama said of the ceasefire, “but based on past experience, also skeptical that, in fact, the separatists will follow through and the Russians will stop violating Ukraine’s sovereignty and territorial integrity.”

“Pro-Russian separatists must keep their commitments,” Obama told the crowd.

The terms of the agreement have to be “tested,” the president added, and that he expects to “move forward based on what is currently happening on the grounds with sanctions, while acknowledging that, if in the fact the elements of the plan that’s been signed are implemented, then those sanctions could be lifted.”

Taking that approach, Obama said, “is a more likely way to ensure that there is a follow through” on the part of Russia.

One day earlier, a White House spokesperson said that the US is readying a new wave of sanctions to impose against Russia as a result of Moscow’s perceived role in the ongoing crisis in eastern Ukraine, and the EU was expected to do the same, targeting both the federation’s energy and defense sectors.

From the NATO summit, Obama said the ceasefire agreed upon only hours earlier was a result of “both the sanctions that have already been applied and the threat of further sanctions, which are having a real impact on the Russian economy and have isolated Russia in a way we have not seen in a very long time.”

Speaking on behalf of the EU, German Chancellor Angela Merkel said Friday that the latest sanctions being threatened against Moscow by European powers could be rescinded if the ceasefire deal is a success.

“Everything is in flux,” Merkel said. "Therefore we should expect that these sanctions could indeed be put into force, but with the provison that they can be suspended again if this process really takes place," she said, Reuters reported.

According to Pres. Obama, this week’s talks among NATO partners yielded the decision that all 28-member states will now provide security assistance to Ukraine by means of supplying non-lethal supports, including body armor, fuel and medical care, as well as assistance intended to modernizing Ukrainian forces through improved logistics and command and control capabilities.

Petro Poroshenko, the recently elected president of Ukraine, said “The highest value is human life, and we must do everything possible to stop the bloodshed and put an end to suffering.”

The United Nations estimated last month that roughly 2,600 people have died in eastern Ukraine since fighting intensified in April.