He argued that the deals were terribly negotiated, ripping off the USA and hurting American workers and manufacturing.
Trump directed officials to explore rejoining an Asia-Pacific trade pact he withdrew from shortly after taking office and expressed optimism about a deal with China, a shift in tone that boosted sentiment in the markets.
Trump had tweeted that the United States would only join TPP if the deal were substantially better than the deal offered to former president Barack Obama.
The 11-nation trade deal, which was renamed the Comprehensive and Progressive Agreement for Trans-Pacific Partnership after the USA withdrew, was signed in March but won't come into force until it's ratified by individual nations. "This whole trade thing has exploded ..."
Trump, in his earlier tweet, said the United States "would only join TPP if the deal were substantially better than the deal offered to President (Barack) Obama". China has responded to Trump's threat of tariffs on as much as $150 billion worth of Chinese goods by placing its own tariffs on USA pork and threatening taxes on soybeans, sorghum, corn and beef. And I think the president realizes, as President Obama did, that having closer links economically with those countries increases our defense capabilities and readiness. "We already have BILATERAL deals with six of the eleven nations in TPP, and are working to make a deal with the biggest of those nations, Japan, who has hit us hard on trade for years!"
The remarks were another conciliatory signal from the administration following tit-for-tat tariffs proposals from the world's largest two economies that rattled markets.
Trump also indicated that talks are progressing toward successful renegotiation of the North American Free Trade Agreement.
The S&P 500 Index closed up 0.8 percent and the Dow Jones Industrial Average added nearly 300 points, or 1.2 percent, as investors assessed the changing trade dynamics.
Withdrawing from the deal was one of Mr Trump's first acts as president, delivering one of his core campaign promises.
"But, for Malaysia, we have gone very far in the negotiations and that is the maximum that we can go".
Members of the partnership, including officials from Japan and Australia, seemed hesitant to accept Trump's possible change of heart.
Republicans in Congress have also been skeptical of Trump's tendencies on trade, and 25 Republican senators sent a letter to Trump urging him to re-engage with the pact "so that the American people can prosper from the tremendous opportunities that these trading partners bring". AFL-CIO President Richard Trumka, head of the main trade union group, said on Twitter that TPP "was killed because it failed America's workers and it should remain dead". A commerce ministry spokesman said negotiations were impossible under "unilateral coercion" by President Donald Trump's government. Trump rooted his campaign in correcting what he saw as unfair trade practices that were hurting American workers and manufacturers, and, very soon after taking office, Trump signed an executive order that withdrew the USA from the partnership.
The Trump administration says it has ordered the Agriculture Department to create a program to help farmers hurt by trade.