By Jared A. Favole Of DOW JONES NEWSWIRES WASHINGTON (Dow Jones)--U.K. Prime Minister David Cameron said Tuesday he understands the deep frustration Americans have with U.K. oil giant BP Plc (BP, BP.LN) over the Gulf of Mexico disaster. Cameron said BP should "rightly be blamed" for an oil spill that he characterized as a catastrophe. The prime minister, in his first official visit to the White House, said he and President Barack Obama discussed the BP oil spill "at length." BP is taking steps to cap the well and pay for damages done to people who rely on the Gulf, Cameron said. -By Jared A. Favole, Dow Jones Newswires; 202.862.9256; jared.favole@dowjones.com (END) Dow Jones Newswires July 20, 2010 14:38 ET (18:38 GMT)