President Obama this week during a cross-Atlantic trip will look to build a united front with European allies against Russian President Vladimir Putin, trying to convince an unmoved Kremlin the West will impose serious penalties for further incursions into Ukraine.

Obama arrives in the Netherlands Monday for the start of a four-country, week-long visit in which Russia's annexation of Crimea will overshadow planned talks about curtailing the proliferation of nuclear weapons.

Most importantly, the president will work behind the scenes to convince European allies to go along with stiffer economic sanctions against Putin's regime if the Russian president refuses to back down in Ukraine.

Obama has imposed sanctions on a limited number of senior Russian officials and threatened to target individual sectors of the nation’s economy — but Putin has shown little concern over the punishment.

And without European support, analysts see few options for Obama to alter Putin’s calculations on how actively Russia should wade into Ukraine after already annexing Crimea.

The White House has raised concerns about increased movement by Russian troops near Ukraine, openly questioning the Kremlin's insistence that Russian forces are simply engaging in military exercises there.

Obama on Monday will attend the Nuclear Security Summit at The Hague, before leading talks between the Group of Seven nations — the U.S., Britain, Canada, France, Germany, Italy and Japan — on Ukraine.

The G-7 discussions were organized at the last minute as a way to isolate Russia on the global stage. Russian Foreign Minister Sergey Lavrov, not Putin, is traveling to the Netherlands for the nuclear summit but will be excluded from the gathering on Ukraine.

The planned June G-8 talks, in Sochi, between those seven nations and Russia could be scrapped altogether.

Obama on Monday will also hold a bilateral meeting with Chinese President Xi Jinping and attend a dinner with Dutch King Willem-Alexander.

The president on Tuesday will give a joint press conference with Dutch Prime Minister Mark Rutte, participate in another gathering with Mohammed bin Zayed Al Nahyan, of the United Arab Emirates, and conduct a trilateral meeting with South Korean President Park Geun-hye and Japanese Prime Minister Shinzo Abe.

Obama's focus on Ukraine will continue on Wednesday with a trip to Brussels, home of the EU and NATO headquarters. The White House is billing Obama's speech later that day at a fine arts center in Brussels as the centerpiece of his European trip.

The president on Thursday will travel to the Vatican for long-anticipated discussions with Pope Francis. Obama has trumpeted the work of the pope repeatedly as part of his call to combat income inequality.

Along with Italian Prime Minister Matteo Renzi, Obama will hold a press conference later on Thursday.

And Obama wraps up his travels in Saudi Arabia Friday, meeting with King Abdullah in Riyadh. Those talks will focus primarily on the administration's attempts to curtail Iran's nuclear ambitions.