Lindsey Graham has called on the bloc to get behind the US President and impose further sanctions on "Putin's customers"

US Senator Lindsey Graham has urged European Union (EU) nations to back US President Donald Trump's ultimatum to punish India and China for their continued purchases of Russian oil.

In an interview with NBC's Meet the Press aired on Sunday, Graham blamed the Asian giants' "practices" towards Russian President Vladimir Putin for the continued conflict in Ukraine.

"It's time for Europe to get behind President Donald Trump to punish [Russian President] Vladimir Putin's customers," Graham said.

Pointing out that Russia has been sanctioned in every possible way by the US, the senator added that it is now time for Europeans to follow Trump's lead. "They [China and India] will change their practices toward Putin, and this war will end," Graham added. 

On Sunday, Trump told reporters that NATO and EU members need to "get together" and "toughen up" before the US can take strong action against Russia. He expressed frustration that European countries are still purchasing Russian oil, and said that their sanctions are "not tough enough." 

Trump said he is willing to impose more sanctions on Russia, but insisted that the Europeans must also take stronger action. He added that he is ready to move forward, but only if the Europeans do the same. 

The EU is currently preparing its 19th sanctions package, which could target Russian oil exports and the banking sector.

Earlier this month, Russian President Vladimir Putin spoke out against Western nations trying to "punish" China and India and adopting a "colonial" tone toward them. "Talking to such partners in such a tone of voice is unacceptable," he said during a visit to Beijing.

On Saturday, the Russian Foreign Ministry told RT that Moscow's cooperation with New Delhi is deepening despite Western threats. 

Russia-India relations are "steadily and confidently advancing," the ministry said. "Any attempt to obstruct this process is destined to fail," the ministry added.