Lebanon's Defence Minister, Elias Murr, has said he will reject US military aid if it comes with a condition that any weapons are not used against Israel.
"Those who want to help the army on the condition that it does not protect its territory, people and border... should keep their money," Mr Murr said.
He was responding after the US House of Representatives blocked $100m of aid.
It came a day before last week's clash on the Lebanon-Israel border which left three soldiers and a journalist dead.
Iran and Syria, supporters of the Lebanese Shia Islamist Hezbollah movement, have since reaffirmed their support for the Lebanese army.
On Monday, the chairman of the US House Foreign Affairs Committee, Howard Berman, said he had used his legislative prerogative to suspend assistance to the Lebanese armed forces on 2 August.
He cited concerns in Congress about the weapons purchased with the aid being turned on Israel and Hezbollah's influence over the army.
The deadly gun battle on 3 August - which resulted in the deaths of two Lebanese soldiers, a Lebanese journalist and a senior Israeli army officer - had only reinforced his decision, he added.
On Wednesday, Mr Murr said that if the congressman "wants to stop, it's upto him".
"Anyone who would like to help the army without restrictions or conditions, is welcome," he told a news conference at the defence ministry in Yarze, near Beirut.
"But those who want to help the army on condition that it doesn't protect its territory, people and border from Israel should keep their money - or give it to Israel instead."
"We will confront Israel with the capabilities we have," he added.
The clash on the Israel-Lebanon border - the most serious incident between the two states since the 2006 conflict between Israel and Hezbollah - began after an Israeli soldier tried to remove a tree which both sides claimed was in their territory.
The United Nations Interim Force in Lebanon (Unifil) has said Israeli soldiers were operating on their own side of the border, but acknowledges that the boundary is contested.
After the confrontation, the Lebanese government launched a campaign to try to build up the nation's under-equipped army.
US State Department spokesman PJ Crowley said on Tuesday that he was not aware of plans to re-evaluate US military co-operation with Lebanon, which he said "contributes to stability in the region".
Since 2006, the US has provided $720m to Lebanon in military aid.