Hillary and Bill Clinton slammed Donald Trump Monday for 'creating a diplomatic incident' and 'damaging America' with last week's meeting with Mexican President Enrique Peña Nieto.

After the meeting, which took place in Mexico Wednesday, Trump told press that he and Nieto had not discussed his long-promised plan to make Mexico pay for a wall between itself and the USA.

'He didn't raise it, so he did choke. He didn't know how to even communicate effectively with a head of state. And I think that's a pretty clear outcome from that trip,' Hillary Clinton told ABC Monday.

'Incident': Hillary Clinton (pictured at a Cleveland, Ohio rally Monday) says Donald Trump's visit to Mexico last week caused a 'diplomatic incident'

'Choked': Clinton says Trump 'choked' when he - by his own admission - didn't bring up his proposed wall during his meeting with Mexican President Enrique Peña Nieto (left)

'Damaging': Bill Clinton (pictured campaigning in Detroit Monday) said Trump 'damaged America' when he told supporters on returning to US that he would make Nieto pay for the wall

Clinton repeated her remarks in Illinois on Monday evening, saying: 'He couldn't even bring himself to tell the president of Mexico one of his very few policy demands.'

And Bill Clinton, who was campaigning for his wife in Detroit, was similarly disparaging about Trump - particularly his rally in Arizona immediately after the Mexico visit, in which he once again promised to make Mexico pay for the wall.

'I've had that job,' the former president said, according to ABC. '(Trump's visit) damaged America and every serious country in the world.

'You cannot be the leader of a country, go down and be nice to people and then come home and dump on them for your own political benefit.'

In his own press flight, Trump sounded less certain about his plan to repatriate all 11million undocumented immigrants than he had when announcing it last Wednesday.

When asked by ABC whether some might be able to stay, Trump said: 'It could be, but what’s going to happen is if you’re going to be a citizen, you’re going to leave and you're going to have to come back.'

And if they don't want to become citizens, he said, 'they have to make a determination what happens when the border is secure.'

'So you’re open to them staying here undocumented?' Trump was asked.

'I’m going to make a decision, or somebody will,' he replied, 'Whether it’s me or somebody else because by that time we’ll have a secure border, we’ll have a wall.'

Uncertain: Trump sounded less certain about his plans to repatriate all 11m undocumented immigrants Monday, when he said that some may be left in the country even if his wall goes up

The Clintons weren't the only ones getting digs in at Trump for his Mexico visit. Senator Tim Kaine, who was also taking part in the ABC interview with Hillary Clinton, also criticized the Republican candidate.

He said: 'If you're gonna cave when you're with an ally, and Mexico's an ally, what are you gonna do when you're with an adversary?'

'You shouldn't leave the safety of America and our diplomacy in the hands of a rookie who, on his one visit with a foreign leader, has already created kind of an international embarrassment for us,' he continued.

'Caving': Senator Tim Kaine (pictured center), who was with Clinton during the interview (pictured) said if Trump 'caved in' with an ally, he couldn't be trusted to stand up to an enemy

The Clintons' remarks take at face value Trump's claim that he did not discuss his proposed wall with Nieto.

But Nieto himself denied Trump's claim on Twitter after their meeting, saying in Spanish: 'At the beginning of the conversation with Donald Trump I made it clear that Mexico will not pay for the wall.'

Hillary Clinton also told ABC that she would not accept Nieto's invitation to visit Mexico herself, saying she would rather focus on the US.