Lukashenko said North Atlantic Treaty Organisation tanks and planes had been deployed 15 minutes from the Belarusian border and neighbouring countries were ordering the country to hold new elections, something he said he refused to do.
Ties between the two traditional allies had been under strain before the election, as Russian Federation scaled back the subsidies that propped up Lukashenko's government.
Statements by both sides contained a pointed reference to a "union state" between the two countries.
The Kremlin said only that the leaders had agreed in a phone call that the "problems" in Belarus would be "resolved soon", with no mention of specific support for Mr Lukashenko.
She is also demanding authorities be held to account for the crackdown, which saw police use rubber bullets, stun grenades and, in at least one case, live rounds to disperse protesters, with at least 6,700 people detained and hundreds injured.
The leaders of the three ex-Soviet Baltic states - Estonia, Lithuania and Latvia - on Saturday condemned the crackdown and called for a new vote.
"We don't need any foreign governments or mediators", Lukashenko was quoted by the BelTA state news agency as saying at a meeting at the Defense Ministry's strategic control center on Saturday.
"We won't give away the country!" he said, while his teenage son Nikolai stood watching nearby.
Other state employees, including police officers and state TV staff, have also come out in support of the protests.
Earlier on Saturday, thousands of people waved flags, lit candles and laid flowers at the scene close to the metro station where one of the protesters, Alexander Taraikovsky, died on Monday.
Covid 19 coronavirus: Can you catch the virus from frozen food?
The CDC recommends washing your hands thoroughly with soap and water after handling food, or before cooking and eating food. This followed China's announcement that it had detected traces of the coronavirus in frozen chicken imported from Brazil.
But this year, protesters fed up with the country's declining living standards and Lukashenko's dismissal of the coronavirus pandemic have posed the biggest challenge to his 26-year rule. She has called on a Belarusian human rights organization for help, and wants global experts to take part in a probe.
Belarusian President Alexander Lukashenko says that Russian Federation has agreed to offer security assistance in the case of external military threats.
On August 13, the United Nations also condemned Lukashenko's government for its treatment of protesters following the latest election, with experts saying: "The Government of Belarus has been impervious to all calls - including our own - to stop crackdowns on peaceful protesters".
He said: "Defending Belarus today is no less than defending our entire space, the union state, those who roam the streets, majority do not understand this".
Many who were released spoke of brutal beatings and other abuse by police, and some showed bruises on their bodies.
She also announced she was setting up a co-ordination council to help ensure a "peaceful transition of power".
President Lukashenko has voiced a grim warning to Belarusians, telling citizens to stay at home to avoid becoming "cannon fodder". He says foreign interference is to blame for the unrest.
The 65-year-old has ruled Belarus with an iron grip and claims to have won the election with 80 percent of the vote. Despite holding some of the country's largest rallies since it was part of the Soviet Union, Tsikhanouskaya emerged with just 10.09% of the August 9 vote, according to the elections commission.
"Former president of #Belarus now asks Putin for help". Ambulances arrived to carry those who apparently were unable to walk on their own.