President Barack Obama said the US is "not looking for Russia to fail," but that a cost must be imposed for its continuing aggression in eastern Ukraine.
Speaking after talks with German Chancellor Angela Merkel, Obama told reporters: "Our preference is for a strong, prosperous, vibrant, confident Russia that can be a partner with us on a whole host of global challenges.
"Unfortunately Russia has made a decision that I think is bad for them strategically, bad for Europe, bad for the world.
"In the face of this aggression and these bad decisions, we can't simply try to talk them out of it, we have to show them that the world is unified in imposing a cost for this aggression."
US President Barack Obama said the prospect of a military solution to the Ukraine crisis "has always been low."
Speaking about the economic sanctions placed on Russia, Obama said they would "not relent" until a diplomatic solution is reached with Russia.
"It has not yet dissuaded Mr Putin from following the course that he is on, but it has created a measurable negative impact on the Russian economy and that will continue," Obama said.
"The possibility of lethal defensive weapons is one of those options that's being examined [should sanctions not work], but I have not made a decision about that," he added.
President Barack Obama has said the US will continue to encourage a "diplomatic resolution" to the Ukraine crisis.
But Obama warned, "If Russia continues on its current course ... Russia's isolation will only worsen both politically and economically".
US President Barack Obama has said it was clear Russia "violated just about every commitment they made" in the Minsk agreement over the situation in eastern Ukraine.
"But Russian aggression has only reinforced the unity of the United States, Germany and our allies and partners around the world", Obama added.
German Chancellor Angela Merkel has arrived at the White House to discuss the situation in eastern Ukraine with US President Barack Obama.
Barack Obama is expected to ask congress to authorise the US military to use more force against Islamic State (IS) militants.
The President has been relying on congressional authorisations that President George W Bush used to justify action after 9/11.
He has been ordering airstrikes in Iraq and Syria for months but further details are being worked out over what America's next move is.
Republican House Speaker John Boehner said: "The president believes it sends a very powerful signal to the American people, to our allies, and even to our enemies, that the United States of America is united behind this strategy to degrade and ultimately destroy IS."
However, Mr Earnest declined to discuss specific provisions being discussed, such as how long the authorisation will last, what geographical areas it will cover and whether it will allow for the possibility of ground troops.
US President Barack Obama is due to meet Jordan's King Abdullah II later today, a source familiar with the situation told Reuters.
The king is cutting short a visit to Washington after news of the killing of a Jordanian pilot by Islamic State militants.
Robbie Keane and his LA Galaxy team-mates met Barack Obama following their Major League Soccer success.
India and the United States have broken an impasse standing in the way of civil nuclear trade, Indian media reports.
The breakthrough comes as Obama and Indian Prime Minister Narendra Modi met in New Delhi.
The reports said that the pair had ironed out differences on the liability of suppliers to India in the event of a nuclear accident and the United States had dropped its demand to be able to track the whereabouts of nuclear material supplied to India.
US President Obama was given an elaborate welcome at the country's presidential palace in New Delhi.
He walked in his socks to place a commemorative wreath honouring the father of India's independence movement, Mahatma Gandhi.
Tomorrow, Mr Obama was to be the guest of honour at India's Republic Day festivities, making him the first US president to attend the anniversary of the enactment of country's democratic constitution.