US Secretary of State Mike Pompeo arrived in Hungary on Monday, on the first leg of a European tour, hoping that economic and defence incentives will dissuade Prime Minister Viktor Orban from getting too close to Russia.

Pompeo is set to meet Orban on the one-day trip to Budapest, from where he will proceed to Slovakia, another NATO ally that has seen a few recent senior US visitors.

The focus of Pompeo's trip to Europe is a US-driven conference on the Middle East in Poland later this week, which has been toned down after European allies were uneasy about promoting President Donald Trump's hawkish line on Iran.

US officials said that Pompeo will discuss ways to increase defence and economic cooperation with Hungary.

While Hungary is treaty-bound to the United States through NATO, US officials are pushing for progress on a bilateral defence cooperation agreement, which would let US forces move freely in the country.

Such an agreement could prove controversial if Hungary is the stage for a US military operation. And it would be sure to irritate President Vladimir Putin, who has considered Orban his closest friend in the European Union.

The United States has also voiced worries over Hungary's growing relationship with China, including an agreement for telecom giant Huawei to develop the country's fifth-generation mobile networks.

Washington has been ramping up pressure on Huawei -- with senior executives of the company arrested in US allies Canada and Poland.

The US has voiced alarm over the direction Hungary has taken in these areas recently, including a decision last year to return two Russian arms dealers home rather than to extradite them to face charges in the United States.

And the prestigious Central European University last year moved its key programmes out of Hungary after the government -- rejecting direct appeals from the US ambassador -- cracked down on educational institutions considered foreign.