Obama's remarks came as he hosted Jordan's King Abdullah II at the Sunnylands retreat in Palm Springs, California, to address issues including the flood of Syrian refugees into Jordan.
The US leader said both he and the Jordanian king "recognise that we can't just treat the symptoms" of the Syrian crisis.
"We're also going to have to solve the underlying problem -- a regime led by Bashar al-Assad that has shown very little regard for the well-being of his people.
"We don't expect to solve this any time in the short term so there are going to be some immediate steps that we have to take to help the humanitarian situation there," Obama said.
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"There will be some intermediate steps that we can take to apply more pressure to the Assad regime, and we're going to be continuing to work with all the parties concerned to try to move forward on a diplomatic solution," he said, without specifying what those steps may be.
At the meeting Obama pledged USD 1 billion in loan guarantees to Jordan, as well as a renewal of a five-year memorandum of understanding.
The funds are aimed in part at helping Washington's Middle East ally cope with the flood of Syrian refugees and its loss of natural gas from Egypt, White House officials said.
King Abdullah said the Syrian crisis and the rise of extremism are his country's primary concerns.
Jordan has borne the brunt of much of the humanitarian overflow, with nearly 600,000 Syrian refugees on its soil, straining its infrastructure and finances.
The United States is the largest aid donor to Syrian refugees, so far donating USD 1.7 billion to the cause, according to the US Agency for International Development.
"It's a signal to the markets of the strong confidence of the United States in Jordan, of our partnership, and of our intention to be there as a partner for Jordan in the long term," said the official, speaking on condition of anonymity.