Trump's call at a G7 summit last month for Russia to be allowed to return to the group was rejected by other members
US Vice President Mike Pence sought on Monday to reassure Poland about Washington's commitment to protecting it from Russia, saying allies should "remain vigilant" about Moscow's election meddling and work towards independence from Russian energy supplies.
In Warsaw for a two-day visit, Pence spoke days after President Donald Trump drew disagreement from US allies by calling for Russia to be readmitted to the Group of Seven advanced industrialized countries.
"With its efforts to meddle in elections across Europe and around the world now is the time for us to remain vigilant about the intentions and the actions being taken by Russia," Pence said.
Trump's call at a G7 summit last month for Russia to be allowed to return to the group was rejected by other members.
Asked about the issue, Polish President Andrzej Duda said Moscow's actions in Ukraine raised a question over whether relations with the country should amount to "business as usual".
"Unfortunately, over the last several years, Russia has taken actions which cannot be ignored by anyone who respects international law," he told a joint news conference with Pence.
"In this context we need to ask ourselves whether this means we can approach Russia in a business as usual way."
Poland is seen as one of Washington's closest allies in Europe and counts on the United States for support, seeing eye on to eye on issues such as climate change, energy and abortion.
The US administration has agreed to increase its military presence on Polish soil, because of nervousness in Warsaw following Russia's annexation of Crimea from Ukraine in 2014.
"We know there is still more work to do on many fronts, because despite years of negotiations Russian forces still illegally occupy large parts of Georgia and Ukraine," Pence told the news conference.
"The truth is Moscow seeks to divide our alliance, now with its oil and gas reserves. Poland has taken a strong stand as we have to promote energy independence and security."
Pence was visiting Warsaw on a trip that was originally scheduled to be by Trump, to commemorate 80 years since the start of World War Two on Sept. 1, 1939. Trump pulled out last week because of the impending hit by Hurricane Dorian.
Pence also signed a cooperation agreement with Poland aimed at making mobile networks immune from espionage. The United States is pressing allies to ban China's Huawei Technologies Co Ltd, the world's top telecommunications equipment supplier, from 5G networks.
The US government says Huawei is able to spy on customers, has violated U.S. sanctions on Iran and stolen American intellectual property. Huawei denies the allegations.