JOHANNESBURG, South Africa (AFP)—Brazil is “very concerned” about a US military build-up near Venezuela, fearing a conflict, President Luiz Inacio Lula da Silva said Sunday, adding he intended to speak with US counterpart Donald Trump about it.

“I am very concerned about the military apparatus that the United States has placed in the Caribbean Sea. I am very concerned, and I intend to discuss this with President Trump because it worries me,” Lula told reporters in Johannesburg after attending a G20 summit.

“I think there is no reason to have a war now,” he said. “Let us not repeat the mistake that happened in the war between Russia and Ukraine. That is to say, once a shot is fired, it is hard to predict how it will end.”

The United States has sent an aircraft carrier strike group, other navy warships as well as stealth aircraft to the region near Venezuela. On Friday it warned civilian aircraft in Venezuelan airspace to “exercise caution”.

US forces have conducted strikes on more than 20 vessels in the Caribbean Sea and eastern Pacific since September, killing more than 80 people. US officials allege they were drug-runners, but provided no evidence.

Washington accuses Venezuelan President Nicolas Maduro of leading a “terrorist” drug cartel, and Trump has not ruled out sending in US soldiers.

Lula, pointing out that Brazil shares a border with Venezuela, said: “It is important that we try to find a solution before it (a potential conflict) starts.”

Trump did not attend the G20 summit in South Africa, boycotting it on the grounds that its priorities — which include boosting cooperation on global trade and on climate change — ran counter to US policies.