WHITE HOUSE - President Donald Trump welcomed Mexican President Andres Manuel Lopez Obrador Wednesday to the White House, where they discussed trade, the economy and immigration, days after a new United States-Mexico-Canada Agreement (USMCA) trade deal among the two countries and Canada went into effect.

They also remarked on the improved relations between the two countries.

"The relationship between the U.S. and Mexico has never been closer than it is right now," Trump said in the Rose Garden before the two leaders signed a joint declaration which "recognizes the advancements our two countries have achieved toward a renewed and strengthened partnership."

The U.S. leader, who in the past has made disparaging remarks about Mexican immigrants and threatened trade tariffs, called the relations between U.S. and Mexico "outstanding," adding that he and Lopez Obrador "put the interests of our countries first."

Lopez Obrador responded, saying: "As president of Mexico, instead of remembering the insults and things like that against my country, we have received from you, President Trump, understanding and respect."

Canadian Prime Minister Justin Trudeau declined to attend the meeting to commemorate USMCA, citing a busy schedule and the inappropriateness of international travel amid the COVID-19 pandemic.

Trump said the U.S. is home to 36 million Mexican Americans and that they make up a "big percentage" of small-business owners.

"They're like you - they're tough negotiators and great businesspeople, Mr. President," Trump told the Mexican leader.

The leftist Mexican president, often referred to by his initials, AMLO, has brushed off domestic criticism for meeting Trump, who is widely disliked in Mexico because of past disparaging remarks about Mexicans and his stance on immigration.

Lopez Obrador's government sees this visit as an opportunity to reaffirm the importance of USMCA and has tried to distance the visit from topics related to immigration.

"It is very important for us to be launching this new agreement, Lopez Obrador said through a translator. "But I also wanted to be here to thank the people of the United States, its government. And thank you, President Trump, for being increasingly respectful with our Mexican fellow men," he added.

In his remarks, Lopez Obrador quoted George Washington, the first U.S. president, who said, "Nations should not take advantage of the unfortunate condition of other people." Lopez Obrador said Trump has "followed" Washington's "wise advice."

Some analysts have noted that Trump has used America's tremendous economic leverage, including threats of tariffs and even a total border closing, to pressure the Mexican leader on issues of trade and immigration.

Mexico functions as a "hinge" between the United States and the asylum-seeker origin countries of Central America, said Maria Fernanda Perez Arguello, associate director at the Atlantic Council. "Immigration from Central America - and the push factors in the countries - is the big elephant in the room between AMLO and Trump," she said.

This is Lopez Obrador's first meeting with Trump and the second visit to the White House by a foreign leader since the coronavirus shutdown in March. Like Trump, Lopez Obrador has downplayed the risks of the coronavirus and said he has never been tested for the coronavirus because he has no symptoms and will take a test only if the White House requires it.

Deputy Press Secretary Judd Deere said that all members of the Mexican delegation, including the president, were tested for the coronavirus and that the tests were administered by the White House.

Speaking to reporters in Mexico City before his departure Tuesday, Lopez Obrador repeatedly said in response to questions about raising issues such as immigration policy that his focus in the talks would be on the trade deal.

"It is always important that there be cooperation for development. But now in a circumstance of global economic crisis, this treaty is going to help us a lot. It is very timely," Lopez Obrador said.

He noted the economic challenges facing Mexico, like those in many other countries during the coronavirus pandemic and stressed the need for Mexico to have good relations with its neighbor.

The Mexican leader noted the agenda for bilateral talks includes other topics, and on those, his delegation - which includes Foreign Secretary Marcelo Ebrard Casaubon and Economic Secretary Graciela Marquez Colin - would not take a confrontational approach, but rather try to have a dialogue of understanding with their U.S. counterparts.

The USMCA updated the 1990s North American Trade Agreement and was a major policy push for Trump, who cast the former trade deal as harmful to U.S. businesses and workers.

The pact includes new laws related to intellectual property protection, the internet, currencies, investment and state-owned enterprises. The new legislation includes more stringent rules on auto manufacturing, e-commerce and labor provisions, but leaves largely unchanged the trade flows among the North American countries valued at $1.2 trillion a year.

In addition to private talks between Trump and Lopez Obrador and wider meetings with their advisers, the two leaders attended a dinner Wednesday night with business leaders from both countries.

Before going to the White House, Lopez Obrador visited the Lincoln Memorial and a statue of former Mexican President Benito Juarez in Washington.