By Stephanie Nebehay and Babak Dehghanpisheh

GENEVA, Oct 29 (Reuters) Iran and Russia on Tuesday condemned U.S. President Donald Trump’s decision to maintain a military presence near oil fields in northeastern Syria, with Russian Foreign Minister Sergei Lavrov saying any exploitation of resources would be illegal.

Trump’s suggestion on Sunday that Exxon Mobil Corp or another U.S. oil company operate Syrian oil fields drew rebukes from legal and energy experts.

The United States will strengthen its military presence in Syria with “mechanized forces” to prevent Islamic State fighters seizing oil fields and revenue, U.S. Defense Secretary Mark Esper said on Friday.

Iranian Foreign Minister Mohammad Javad Zarif addressed the issue at a news conference in Geneva on Tuesday evening after meeting with his counterparts, Russia’s Lavrov and Turkey’s Mevlut Cavusoglu.

“Well it seems that the United States is staying to protect the oil. And at least President Trump is honest to say what the United States intends to do,” Zarif said to laughter.

[aesop_image img=”” panorama=”off” credit=”Turkey’s Foreign Minister Mevlut Cavusoglu, Iran’s Foreign Minister Mohammad Javad Zarif and Russian Foreign Minister Sergei Lavrov attend a news conference, a day ahead of the first meeting of the new Syrian Constitutional Committee at the Untied Nations in Geneva, Switzerland, October 29, 2019. REUTERS/Denis Balibouse ” align=”center” lightbox=”off” captionsrc=”custom” captionposition=”left” revealfx=”off” overlay_revealfx=”off”]

Iran and Russia are there on the invitation of the Syrian government, and we intend to stay there as long as the Syrian government and Syrian people want us to be there,” he said.

Lavrov said that the return of U.S. forces to Syria, after their transfer to Iraq, was “under the pretext of protecting oil deposits from the Islamic State.”

“The essence is that any illegal exploitation of natural resources of a sovereign state without its consent is illegal and that is the view that we share,” he said.

“Our U.S. colleagues are aware of our position and we will defend that position,” Lavrov said.

Fahrettin Altun, Turkish President Tayyip Erdogan’s communications director, said in a tweet later on Tuesday: “Syria’s natural resources belong to Syrians.

“Oil or other types of revenue should be used for reconstruction efforts including local infrastructure, support for civilians, IDPs (internally displaced persons), and refugees. Just as Syrians should be able to determine their own political future, they should also be allowed to decide how the resources of their own land should be spent,” Altun said.

The United States Special Envoy for Syria Joel Rayburn, speaking to reporters in Geneva earlier on Tuesday, voiced concern at what he said was the “continuing dangerous situation in northeast Syria” and urged all sides to work to stabilise the situation.

(Reporting by Stephanie Nebehay and Babak Dehghanpisheh in Geneva Additional reporting by Tuvan Gumrukcu in Ankara Editing by Matthew Lewis)