The White House said President Obama's conversations with Russian President Vladimir Putin were “direct” and “candid,” and that the next few days would reveal if Moscow would de-escalate the Ukraine crisis.

“We're having robust, direct, candid conversations between President Obama and President Putin,” said deputy press secretary Josh Earnest, when asked to characterize the talks. “That means acknowledging that there are basic differences over what's actually happening on the ground in Crimea.”

The two leaders spoke on Thursday for an hour as Obama warned Putin that his military incursion into Ukraine’s Crimean peninsula violated international law, and urged him to seek a diplomatic resolution. It was their second conversation over the last week, with the two speaking for 90 minutes on Saturday.

But the two leaders appear no closer to a resolution, as Putin has rejected calls to pull back his forces and cancel a planned referendum in Crimea on leaving Ukraine and joining Russia.

Russian troops seized Crimea after Moscow-backed former Ukrainian President Viktor Yanukovych was removed from power by Kiev's new interim government.

Putin says that Moscow is only protecting the safety of the region's majority-ethnic Russian population and has even denied that the security forces patrolling Crimea are from Russia. But the administration has rejected those claims.

"There’s a pretty strong difference of opinion; that there is a disagreement about the facts related to what’s actually happening on the ground there," said Earnest.

“The best example of this is — you saw in the news conference that President Putin convened earlier this week that he basically denied that there were Russian troops on the ground in Crimea outside their bases. All of the available evidence indicates that's not true,” he added.

Obama has urged Putin to send Russian troops back to their bases, sit down for talks with the government in Kiev and allow international monitors.

He warned Thursday that the U.S. was pressing ahead with measures to help Ukraine and punish Russia, but said there was still time for a diplomatic solution.

Also on Thursday, Obama signed an executive order allowing for targeted sanctions and visa bans on individuals determined to be “undermining democracy” in Ukraine. The European Union followed suit.

And a Ukraine aid bill that would provide $1 billion in loan guarantees passed the House on Thursday. The administration says the financial assistance will help Ukraine stabilize its economy and ease pressure on the country from Russia, a major trade partner and energy source.

Earnest said the “next few days” should reveal whether Moscow was interested in taking “concrete steps toward this off-ramp here.”

Obama will spend his weekend vacationing in Key Largo, Fla., but the White House said he would be closely monitoring the situation in Ukraine.