Republican White House hopeful Donald Trump insisted Wednesday that Mexico will pay for the border wall he plans to build if he is elected, after holding talks with Mexico's president.

"Mexico will pay for the wall, believe me," Trump said in Phoenix as he laid out his immigration plan that includes deporting immigrants with criminal records and cancelling President Barack Obama's executive orders protecting millions of undocumented immigrants. 

Hours earlier, Trump met with Mexican President Enrique Pena Nieto and said the two did not discuss who would pay for the wall. But Pena Nieto contradicted Trump by tweeting that he told the Republican nominee in their meeting that Mexico would not fund the construction.