The president has made the claim as he defends his administration's new "zero tolerance" policy that calls for the criminal prosecution of all adults apprehended attempting to cross the USA border illegally.
German Chancellor Angela Merkel and Polish Prime Minister Mateusz Morawiecki are scheduled to speak at the Berlin climate meeting this week.
In her fourth term at the helm of Europe's largest economy, Merkel made it clear that she has no intention of being pushed around after an internal power struggle over immigration escalated into a threat to her government.
But speaking after talks with her party, Merkel told media that she would report back on July 1.
Merkel opposes the proposal that comes from a party facing a tough vote in its home base in Bavaria in October against a resurgent far-right Alternative for Germany (AfD), which has advocated harsh anti-immigration line.
For Merkel, who has faced the most serious challenge to her authority in recent days over her handling of the refugee influx of 2015 and 2016, the display of amitié was particularly important.
According to Seehofer's so-called asylum "master plan", Germany should start turning back migrants at the border who previously applied for asylum or registered as asylum-seekers in other European countries.
Driven in part by the civil war in Syria, the number of asylum seekers entering Germany began to rise sharply in 2013, when it reached nearly 110,000, and then soared after Merkel changed the policy in the summer of 2015.
"Germany's Sueddeutsche daily praised the partnership, saying that "with unrest so rife across the EU, Europe can consider itself lucky if it is able to find any common ground at all". Merkel has common sense on her side when she argues that there has to be a European fix.
"[Trump's] zero-tolerance policy is cruel".
Trump, who regularly lambastes Germany in his Twitter tirades, launched an unusually pointed attack on Merkel's coalition on Monday, when as well as asserting that its migration policy was causing crime, he suggested that Merkel was on the ropes.
The European Commission said on Monday it was confident that EU leaders could agree at a summit next week on handling migrants and refugees, but some diplomats were much less optimistic.
Mrs Merkel fears that if Germany reverses its suspension of the Dublin regulations, which state that a country where a migrant entered must deal with the claim, frontline countries like Greece and Italy will be overwhelmed.
The two leaders had made a decision to focus on broad issues to leave more room for negotiations with the other 17 euro members, Macron said - a scenario that leaves scope for the plans to be watered down.
Italy and France have also become involved in the migrant debate, with Italy's interior minister Matteo Salvini, who is the deputy Prime Minister of the country, refusing to accept new refugee boats and calling for asylum seekers to be equally distributed across the European Union, rather than being hosted by the first country they land in.