U.S. Defense Secretary Robert Gates was in Iraq Thursday to meet with Iraqi officials amid a wave of bombings that have claimed 127 lives and rattled the country"s government. U.S. military leaders who greeted Gates defended the Iraqi security forces" response to the attacks, according to AP. A Thursday night meeting between Gates and Prime Minister Nouri al-Maliki was canceled after al-Maliki was summoned before Iraq"s parliament to discuss the bombings. Pentagon spokesman Geoff Morrell said Gates hoped to meet early Friday morning with the prime minister. Gates did meet with Iraqi President Jalal Talabani and offered U.S. help in dealing with the attack"s aftermath. Morrell said Gates told the Iraqi president, «The bombings are a tragic reminder it"s not over yet. There"s still work to be done.» The second leg of Gates" previously unannounced tour of two major U.S. war zones came as al-Qaida"s umbrella group in Iraq claimed responsibility Thursday for the strikes. The bombings wounded 500 people; the group warned of more attacks to come. Senior U.S. military officials defended the Iraqi forces" efforts even after al-Maliki expressed his displeasure by dismissing his head of security operations in Baghdad. «It would be tough for any country, any government to prevent these kinds of attacks,» said Lt. Gen. Charles Jacoby, the No. 2 U.S. commander in Iraq. Jacoby said that security vulnerabilities in Baghdad had been exploited in Tuesday"s bombings and called it a «complicated» situation. «There are some obvious gaps» to Iraq"s ability to defend itself, but «they"re committed to it,» he told reporters. Jacoby and other U.S. officials said the attack was a sign that al-Qaida"s grip on the fractured nation was weakening. With fewer fighters, the Iraqi insurgent force has turned its focus from seizing territory to occasional high-profile suicide bombings aimed at destabilizing the government. «I think it"s all about the election right now,» Jacoby said. Regardless, the bombings have raised tough questions for al-Maliki about the ability of Iraq"s security forces ahead of next year"s planned withdrawal of U.S. combat troops. The U.S. says it plans to keep the bulk of its 120,000 forces in Iraq through the country"s March 7 elections to counter violence; but it plans to leave the country entirely by the end of 2011. The claim of responsibility for the Tuesday attacks came in a Web posting from the Islamic State of Iraq, which purports to speak for a range of insurgent factions linked to al-Qaida in Iraq. Its authenticity could not be independently verified. The bombings raised questions about serious gaps in Iraqi security, prompting angry questions from Iraqi lawmakers, who grilled al-Maliki in a closed session of parliament. On Wednesday, al-Maliki pushed aside the military commander overseeing Baghdad security and moved the No. 2 officer into the top spot. Al-Maliki also claimed that feuding between political blocs, coordination troubles between police and army and budget cuts because of falling oil prices have hobbled attempts to expand security operations.