Mexican President Andres Manuel Lopez Obrador turned down Donald Trump's offer to help Mexico 'wage war' on the drug cartels and 'wipe them off the face of the earth' in the wake of a mass murder of American citizens.

López Obrador on Tuesday rejected Trump's approach, saying his predecessors waged war against the cartels 'and it didn't work.'

He told reporters in Mexico he would speak with his American counterpart to thank him for the offer but didn't think U.S. aid was needed.

'I don't think we need the intervention of a foreign government to deal with these cases,' he said.

The White House confirmed the two men spoke on Tuesday.

'Today, President Donald J. Trump spoke with Mexican President Andrés Manuel López Obrador to discuss the recent violence in Mexico and efforts to combat the growing violent behavior of cartels and criminal groups in the region,' said White House deputy press secretary Hogan Gidley in a statement.

'President Trump made clear that the United States condemns these senseless acts of violence that took the lives of nine American citizens and offered Mexico assistance to ensure the perpetrators face justice. The two leaders also discussed ongoing border cooperation and the strong bilateral ties between the United States and Mexico,' he added.

Trump took to Twitter to mourn the three American mothers and six children from a Mormon community based in northern Mexico who were killed in an attack blamed on drug cartel gunmen.

And he offered American help.

'If Mexico needs or requests help in cleaning out these monsters, the United States stands ready, willing & able to get involved and do the job quickly and effectively. The great new President of Mexico has made this a big issue, but the cartels have become so large and powerful that you sometimes need an army to defeat an army!,' Trump wrote on Twitter.

'This is the time for Mexico, with the help of the United States, to wage WAR on the drug cartels and wipe them off the face of the earth. We merely await a call from your great new president!,' he concluded.

Mexican President Andres Manuel Lopez Obrador will call Donald Trump on Tuesday after his offer to help Mexico 'wage war' on the drug cartels

President Donald Trump took to Twitter to mourn the three American mothers and six children from a Mormon community based in northern Mexico who were killed

The expected conversation later Tuesday marks the second phone call in a week between the two leaders.

Lopez Obrador said Saturday he received a phone call from Trump to express 'solidarity' over the events in the northern Mexican city of Culiacan, where the government backed off from an attempt to arrest a drug suspect in the face of extraordinary cartel violence.

The gunfight in the city of roughly 800,000 residents was triggered Thursday by an attempt to arrest Ovidio Guzmán, son of convicted drug lord Joaquin 'El Chapo' Guzmán Loera, in response to a U.S. request for extradition.

Lopez Obrador said he told his U.S. counterpart that 'we Mexicans have to resolve in a sovereign and independent way' matters as delicate as those in Culiacan.

Relations between the U.S. and Mexico have improved remarkably since Trump took office - when he vowed to have Mexico pay for his border wall and officials there refused.

Now the president regularly thanks Mexico for guards it has put on the border and uses that country's cooperation to ding Democrats for not funding his border wall.

'I want to thank Mexico. 27,000 Mexican soldiers policing the border because the Democrats will not do anything,' Trump said at his rally in Lexington, Ky., Monday night in what has become a regular feature in his stump speech.

Additionally, leaders of both nations have pressed for their respective legislative bodies to pass the United States Mexico Canada trade agreement.

The latest call for cooperation comes after the massacre of the LeBaron family, who were ambushed about eight miles apart in the Mexican border state of Sonora on Monday.

At the time of the attack, 17 of the family members were traveling in three cars from La Mora - a breakaway settlement founded decades ago in northern Mexico as part an offshoot of The Church of Jesus Christ of Latter-Day Saints.

There are reports some of the family members, who were dual U.S.-Mexico citizens, were heading to celebrate a wedding anniversary.

Several family members have since described horrific scenes, including how gunmen opened fire on one child running away and others burning to death inside a car that was torched.

Other young children managed to escape and hide by the roadside while one of the mothers was shot in the chest as she put her hands up to surrender. Relatives fear some of the victims may have been raped.

One family member has described how a boy managed to hide his wounded siblings - some less than a year old - in bushes before he ran back to the nearby town to get help after his mother was gunned down.

It was unclear what motivated the killings, which took place on a dirt road between Chihuahua and Sonora states, both bordering the United States. Family members believe it was an attempted kidnapping after one relative reported receiving a phone call hearing screams before they were executed.

At least three American mothers and six children from a Mormon family were killed in a shooting in the Mexican border state of Sonora on Monday. The LeBaron family are among those dead

Two of LeBaron's other children, Howard Jacob, 12, and Krystal, 10, were also killed. Ruthila E LeBaron posted a photo of her sister and her children, Howard Jacob, 12, and Krystal, 10, were also killed. She said: 'My beautiful sister and her sweet babies'

Rhonita Maria LeBaron reportedly died along with her twin 6-month-old babies and two other children in an attack in Mexico Monday

Rhonita Maria LeBaron was traveling to Phoenix when her car broke down, according to relatives

Family members say Rhonita Maria LeBaron was driving to Phoenix on Monday with her four children to pick up her husband and then return to Mexico to celebrate their wedding anniversary.

The relatives say her car had broken down when gunmen opened fire and torched her vehicle causing the gas tank to explode.

She was killed along with her twin six-month-old babies, Titus and Tiana, her 10-year-old daughter Krystal and 12-year-old son Howard.

A video posted on social media showed the charred and smoking remains of the vehicle riddled with bullet holes that was apparently carrying the victims when the attack happened.

'This is for the record,' a male voice with an American accent can be heard saying while filming the clip.

'Nita and four of my grandchildren are burnt and shot up,' he said.

Eight miles away in different attacks, several other family members were gunned down.

Christina Langford Johnson, 29, Dawna Ray Langford, 43, and two of Dawna's children, Trevor, 11, and Rogan, 3, also died while while traveling in two other SUVs.

Family members say Christina saved her seven-month-old baby Faith's life by throwing the infant to the floor of their SUV as bullets tore through the vehicle. Relatives say the baby had been in the back of the car all day before rescuers found her.

Seven of Dawna's children survived but suffered multiple gunshot wounds, according to relatives.

The shooting occurred near the town of Bavispe between Sonora and Chihuahua near the US-Mexico border

Trish Cloes (left) pictured with her niece, dead victim Dawna Langford (right) whose children, Trevor, 11, and Rogan, 3, were also killed in other SUVs. Seven of her children survived

Dawna Langford, (center blue dress) was killed along with two of her children, while seven of her more of her children escaped

A convoy of three vehicles had set out Monday from La Mora and were attacked by cartel gunmen in what he said may have been a case of mistaken identity

Relatives have since taken to social media to share horrific details of the attack, including fears that some of the victims were raped.

They also described how one mother got out of her car during the siege and put her hands up to surrender before being shot in the chest at point blank range.

They described how the injured children were left abandoned on the dirt road by their attackers.

The Mexican government deployed the army to fight drug trafficking in 2006, but experts blame the so-called 'drug war' for the spiraling violence between fragmented cartels and the military, which has lead to more than 250,000 murders.

Missing: Family members have taken to Facebook to get the word out about their dead and missing relatives

The Chihuahua state attorney general, Cesar Augusto Peniche, said the number of victims killed in the attacks remains 'confused'.

Authorities in Sonora state and the U.S. Embassy did not immediately respond to requests for comment.

The federal Department of Security and Citizens' Protection said security forces were reinforced with National Guard, army and state police troops in the area following 'the reports about disappearance and aggression against several people.'

The U.S. Ambassador to Mexico Christopher Landau said in a tweet in Spanish that 'the safety of our fellow citizens is our top priority. I am closely following the situation in the mountains between Sonora and Chihuahua'.

Claudia Pavlovich Arellano, the governor of Sonora, said on Twitter late Monday that 'as a mother,' she was filled with deep pain by 'the cowardly acts in the mountains'.

'I don't know what kind of monsters dare to hurt women and children,' she wrote.