ttip protesters hanover germany
Protesters rallying against the TTIP and CETA free-trade agreements march on the eve of a visit by U.S. President Barack Obama on April 23, 2016 in Hanover, Germany. Sascha Schuermann/Getty Images

German Chancellor Angela Merkel and U.S. President Barack Obama said Saturday they favored sealing a U.S.-European free trade agreement, as it would fuel growth on both sides of the Atlantic.

Merkel is expected to discuss the Trans-Atlantic Trade and Investment Partnership (TTIP) with Obama when he visits a trade show in Hanover on Sunday and Monday. Support for TTIP has plunged in both their countries, however.

Tens of thousands of protesters marched in Hanover on Saturday to express their opposition to the deal. Police said 35,000 people took part in the demonstration, while organizers said more than double that number had attended.

Protesters held placards reading "Stop TTIP" and "For a fair world trade."

"The Trans-Atlantic Trade and Investment Partnership is one of the best ways to promote growth and create jobs," Obama told the mass-selling newspaper Bild in an interview.

Merkel said in her weekly podcast that wrapping up a deal would be a "win-win situation," adding that "it is good for us, as we will be able to appraise our competitors."

The United States is Germany's biggest trading partner. Advocates of the trade deal say it would unleash further growth, while critics warn it could undermine consumer rights and environmental protection.

Speaking separately in London on Saturday, Obama said the trade deal had run up against "parochial interests" of individual countries but would create millions of jobs and billions of dollars in benefits.