The coalition of 16 US states is led by California attorney general Xavier Becerra.
This after the US president invoked a national emergency to tap into military and other funds to build the wall.
VP Mike Pence's trip to Europe deepened divisions with traditional allies over Iran and Venezuela.
UPDATED 11AM | US president risks plunging into a lengthy legislative and legal battle with Democrats.
A supporter pushed the journalist and cursed him.
However, it does not include the US$5.7b Trump wants for a border wall.
It seems to me Trump's going to have to go it alone, by declaring an emergency, says Lindsey Graham.
800,000 federal employees returned to work yesterday, after 35 days without pay.
The US president makes a bid to end a 30-day partial government shutdown.
The venue is yet to be decided with speculations that it could be Bangkok or Singapore.
US president says there is a growing security and humanitarian crisis at the US-Mexico border.
The meeting comes days after N Korean leader warned of 'new path' if US does not ease sanctions.
He is said to be considering declaring a national emergency to bypass Congress and build the wall.
'He can expect a strong and swift challenge from all of us, and from the American people,' says a Congressperson.
US-backed forces still retaking territory from IS, two weeks after Washington announced withdrawal.
They flex their muscles by ignoring the president's demand for US$5 billion for the border wall.
The meeting with Congress leaders broke off after the president stuck to his US$5b border wall funding demand.