WASHINGTON President Barack Obama and Mexican President Felipe Calderon vowed greater cooperation to combat drugs and arms smuggling and ease trade tensions as they sought to smooth over cross-border differences.
Long-simmering problems between the United States and Mexico have slipped down Obama's agenda as he has been distracted by Middle East unrest, a budget fight in Congress, a fragile U.S. economy and his looming 2012 re-election bid.
But Calderon's visit has been a chance to refocus Obama's attention on bilateral ties, and the leaders announced an agreement on a way to resolve a long-haul trucking dispute that has hurt trade between the two countries, whose two-way commerce surpasses $1 billion a day.
Beyond that, however, their White House talks yielded little more than renewed commitments to the U.S.-Mexico drug war alliance, where cracks have recently appeared.
Calderon raised eyebrows in Washington last week when he accused the United States of damaging efforts to beat back drug cartels, just days after one Immigration and Customs Enforcement agent was killed and another wounded in one of the worst attacks on U.S. officials in Mexico.
Calderon did not repeat those complaints when he appeared side by side with Obama at a White House news conference.
But Obama made clear he had heard Calderon's appeal to do more to crack down on U.S. drug consumption and illegal arms shipments and cash flow to Mexican gangs, which the Mexican government says is fueling violence south of the border.
While insisting that Washington had already ramped up its efforts in those areas, Obama told reporters: "We have to take responsibility just as he's taking responsibility ... We're putting more and more resources into this."
Since Calderon launched a war on the cartels in 2006, more than 36,000 people have been killed, putting pressure on Mexico and the United States to beef up their response.
The spiraling violence worries foreign investors and makes some tourists nervous about visiting Mexico, and drug-related abductions have spilled over to the U.S. side of the border.
Intelligence sharing has increased but mistrust between security forces has hampered progress. Mexico's resources are stretched and the United States has limited options.
Calderon's visit -- his first since an official state visit in May -- came after a Mexican newspaper interview in which he lashed out at ICE, the CIA, and the Drug Enforcement Administration. "The reality is that they don't coordinate with each other, they're rivals," he told a Mexican newspaper.
In diplomatic cables published recently by anti-secrecy website WikiLeaks, U.S. officials said in January of last year that Mexican authorities were not working together to bring the cartels to heel.
Despite that, Obama used Calderon's visit to praise Mexican law enforcement cooperation in the investigation of the killing of ICE agent Jaime Zapata.
While the death prompted calls from U.S. lawmakers that U.S. agents in Mexico should be allowed to carry guns, Calderon said any decision would have to be made by Mexico's Congress.
Obama voiced respect for Mexican sovereignty but said his administration was looking at ways to improve agents' safety.
Despite the roiled diplomatic waters, the leaders mostly papered over differences and sought to strike a unified front.
There were no new initiatives on issues like illegal immigration, a long-standing irritant in relations.
Obama reaffirmed his commitment to overhauling what he called a "broken" U.S. immigration system that would offer both improved border enforcement and measures to ease the plight of millions of undocumented Mexican workers in the United States.
But he gave no time-frame for such an effort, and there are strong doubts he will launch major new reform legislation on the hot-button issue as his 2012 re-election bid approaches.
Trade loomed large, given that Mexico sells 80 percent of exports to its neighbor and the countries -- along with Canada -- are parties to the North American Free Trade Agreement.
The cross-border trucking proposal, which must be approved by U.S. lawmakers and is still being finalized, would lift Mexican tariffs on $2 billion worth of U.S. goods and boost hiring on both sides of the border, the White House said.
(Additional reporting by Dave Graham in Mexico City and Jeremy Pelofsky, Doug Palmer and Jeff Mason in Washington; editing by Mohammad Zargham)