"Be careful in your choice. Do not let those come into office with people's votes who would want to surrender to our enemies and make the nation lose its dignity," he said in a televised speech in the western province of Kordestan.
Khamenei said that it would be a "catastrophe" for Iran if a candidate who "thinks about endearing himself to some Western power or an international arrogant" is elected next month.
"(Vote not for) those who would want to flatter the West and bullying Western powers in order to gain a position in the international arena. These things are of no value to the Iranian people."
His latest remarks again indicate Khamenei's support for hardline incumbent President Mahmoud Ahmadinejad, who is seeking a second four-year term in office in the June 12 poll.
Ahmadinejad's presidency has seen the Islamic republic adopt an aggressive stance towards Western powers, especially the United States.
Despite gestures such as congratulating President Barack Obama on his victory and writing to world leaders including former president George W Bush, the firebrand Ahmadinejad is famous for his opposition to Washington.
In the presidential election he will stand against former prime minister Mir Hossein Mousavi, ex-parliament speaker Mehdi Karroubi and former Revolutionary Guards head Mohsen Rezai.
All three have publicly said that they prefer dialogue, interaction and a policy of detente with the West which is at loggerheads with Tehran because of its controversial nuclear ambitions.
Western powers fear Iran is secretly trying to build nuclear weapons, a charge denied by Tehran which says its nuclear programme is for civilian use.
In a similar speech last Tuesday Khamenei again implicitly supported Ahmadinejad, without naming him.
"We should elect those who have popular support and who live in a simple and modest way… are pained by the pain of the people," he said in an apparent reference to Ahmadinejad who is known for his modest lifestyle.
"They should be close to people, be away from corruption. They should not be aristocrats themselves so to push people toward aristocracy," he added. "I think these are important features."
Last year Khamenei also indicated he would back Ahmadinejad.
In August, he said in a speech to the Ahmadinejad government that it must make "plans for the next five years."
On Monday Khamenei also urged the people to vote for a candidate who believes in the "principles of the revolution" and "in the path of Imam" Khomeini, founder of the Islamic revolution.
In 1979, Ayatollah Ruhollah Khomeini led the revolution in Iran that toppled the US-backed shah. The United States and Iran have had no diplomatic relations since 1980.
