White House press secretary Sean Spicer said the two leaders discussed the new schedule by phone on Monday, hours before a snowstorm is set to hit the East Coast.
The first face-to-face meeting between Trump and Merkel is highly anticipated because the two leaders have raised questions about each other in past months.
During his presidential campaign, Trump criticized Merkel over Germany's refugee policies. In late 2015, the president expressed irritation when Time magazine named the German chancellor its Person of the Year (an honor Trump won last year).
Merkel has questioned Trump's skepticism of global trade deals and the NATO military alliance.
"I am deeply convinced that the trans-Atlantic partnership based on common values is in all of our interests, not only for us Europeans," Merkel said in previewing her meeting at the White House. "I'll hold my talks with President Donald Trump in this spirit."
Trump and Vice President Pence, who met with Merkel at a security conference last month in Munich, have since expressed support of NATO but said European members should bear more of the costs of the military alliance.
The new president and the chancellor spoke by phone in late January, a conversation that included the future of NATO, the Middle East and relations with Russia.
"Both leaders affirmed the importance of close German-American cooperation to our countries' security and prosperity and expressed their desire to deepen already close German-American relations in the coming years," said a White House statement on the call.
Read Trump-Merkel meeting pushed back to Friday