MEXICO CITY (Reuters) - Mexico's Foreign Minister Marcelo Ebrard said he started negotiating with officials in Washington on Friday after U.S. President Donald Trump threatened tariffs on imports of Mexican products but face-to-face talks will not happen until next week.

Ebrard said on Twitter that he had spoken to senior White House adviser Jared Kushner and U.S. Secretary of State Mike Pompeo by phone, and that there was a willingness to resolve the dispute.

"The negotiations have started," Ebrard said before boarding a plane to Washington. "I heard interest and respect about the letter from President Lopez Obrador. We are moving forward."

However, Ebrard said in-person talks would not take place until Wednesday in Washington, and that Pompeo would lead the U.S. delegation. Ebrard will be accompanied by deputy foreign minister for North America, Jesus Seade, a veteran trade negotiator.

Mexican President Andres Manuel Lopez Obrador said earlier on Friday that he would respond with "great prudence" to Trump's threats to impose punitive tariffs on Mexican products on June 10.

Trump has accused Mexico of not doing enough to stop the flow of illegal immigration from Central America to the United States but Lopez Obrador said his migration policy was already producing results.

(Reporting by Stefanie Eschenbacher; Editing by Cynthia Osterman)