U.S. officials on Tuesday challenged Russian President Vladimir Putin's claim that Moscow's hands are tied when it comes to NSA leaker Edward Snowden, saying there is a "clear legal basis" to turn him over.

Putin confirmed earlier Tuesday that Snowden is at the Moscow airport. He said, though, that not only is Snowden in the transit zone, but since Snowden has not committed a crime in Russia, the government will not extradite him back -- as requested -- to the United States.

Putin, speaking at a press conference in Finland, also said he hopes the Snowden case will not affect relations with the United States. He then dismissed U.S. accusations against Russia over the Snowden case as "rubbish," and added that Russian security agencies "didn't work and aren't working" with Snowden.

Commenting on the U.S. request to extradite him, Putin said Russia doesn't have an extradition agreement with the U.S. and thus wouldn't meet the U.S. request.

Caitlin Hayden, a spokeswoman for the White House National Security Council, said the absence of a treaty should not matter.

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"While we do not have an extradition treaty with Russia, there is nonetheless a clear legal basis to expel Mr. Snowden, based on the status of his travel documents and the pending charges against him," she said. "Accordingly, we are asking the Russian Government to take action to expel Mr. Snowden without delay and to build upon the strong law enforcement cooperation we have had, particularly since the Boston Marathon bombing."

U.S. Secretary of State John Kerry also acknowledged there is no extradition treaty with Russia, but said there are standards of behavior between nations. He said Russia should not side with an international fugitive.

"There is respect for rule of law, and we would simply call on our friends in Russia to respect the fact that a partner nation ... has made a normal request under legal systems for law to be upheld," Kerry said. "We're not looking for a confrontation. We're not ordering anybody. We're simply requesting, under a very normal procedure, for the transfer of somebody."

Other lawmakers urged the U.S. to be more forceful. Sen. Lindsey Graham, R-S.C., said the U.S. should "stand up to Putin."

"They're defying us and the world, and I expect us to push back. I've had it with this," Graham said.

Earlier Tuesday, Russia's foreign minister Sergey Lavrov said Snowden hadn't even crossed into Russian territory as he pushed back on U.S. demands.

"We consider the attempts to accuse Russia of violation of U.S. laws and even some sort of conspiracy, which on top of all that are accompanied by threats, as absolutely ungrounded and unacceptable," Lavrov said. "There are no legal grounds for such conduct of U.S. officials, and we proceed from that."

The comments kicked off a full day of competing statements in the escalating stand-off between the two countries over the globetrotting fugitive.

The leaker's evasion of U.S. extradition efforts has added another headache for the Obama administration as it grapples with the steady pace of intelligence leaks that Snowden has set into motion. The administration is trying -- strenuously, it appears -- to convince a string of countries not known for their friendliness toward the U.S. to keep Snowden in one place while they negotiate his status.

Julian Assange, the WikiLeaks founder whose team is assisting Snowden, said on Monday that Snowden has applied for asylum in Ecuador, Iceland and possibly other countries. Meanwhile, Ecuador's foreign minister said Monday that the country was considering Snowden's request.

Graham on Monday also wrote a terse letter to Russian Ambassador Sergey Kislyak saying that, if Snowden is still in Russia, Moscow should turn him over.

"The Snowden case is an important test of the 'reset' in relations between our two countries. Mr. Snowden's own statements have made clear his guilt. If our two nations are to have a constructive relationship moving forward, Russian cooperation in this matter is essential," he wrote. "If Mr. Snowden is still on Russian territory, I urge your government to apprehend him and turn him over to the United States authorities immediately."

Ecuador's Foreign Minister Ricardo Patino spoke to reporters while in Vietnam on Monday, saying his country is analyzing Snowden's request. He was critical of the U.S., saying it's unlikely Snowden would receive a fair trial.

He said earlier that the asylum request "has to do with freedom of expression and with the security of citizens around the world."

Snowden helped The Guardian and The Washington Post disclose U.S. surveillance programs that collects vast amounts of phone records and online data in the name of foreign intelligence, but often sweeping up information on American citizens. Officials have the ability to collect phone and Internet information broadly but need a warrant to examine specific cases where they believe terrorism is involved.

The Associated Press contributed to this report.