Homeland Security Secretary Janet Napolitano flew to Louisiana with other officials and urge the British oil and gas giant to use "additional assets to help lead the response in this effort".
"We will continue to push BP to engage in the strongest possible response," she said.
In a statement from the White House on Friday, President Obama said BP was "ultimately responsible... for paying the costs of response and clean-up operations".
BP Chief Operating Officer Doug Suttles defended the firm's actions, saying it had mounted "the largest response effort ever done in the world".
The oil giant is sending teams underwater with remotely operated vehicles to try to shut off an underwater valve, but so far they have been unsuccessful.
They are also having a relief-well drilled to decrease the pressure and slowing the leak, though experts say that could take up to three months.
The US government said on Friday it was putting on hold all new offshore drilling until the cause of the spill is investigated.
Last month President Obama eased a moratorium on new offshore drilling.
The US government has designated the oil spill an "incident of national significance", allowing it to draw on resources from across the country.
How the oil has spread Approximate oil locations 22 April - 15 May
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BP is ultimately responsible
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