( CNN ) -- In his first visit to Israel and the West Bank since assuming the White House , President Barack Obama ventures into a region of the world whose politics are layered and complex . As he meets with Israeli Prime Minister Benjamin Netanyahu , Obama will address problems on many levels , including his chilly relationship with Netanyahu , Iran 's growing nuclear threat , Syria 's possible use of chemical arms and the elusive prospect of peace between Israel and the Palestinians . The to-do list is ambitious . Obama is n't expected to unveil a major peace plan , but the four-day visit will help define the two-term president 's legacy in the Mideast . 1 . Repairing personal politics . Netanyahu and Obama sometimes have been at odds . Netanyahu was perceived by the Israeli left as supporting Obama 's opponent , Mitt Romney , in last fall 's election . Netanyahu 's administration also was perceived as slighting the Obama administration when Israel issued permits for settlement building while Vice President Joe Biden was visiting in 2010 . For Obama 's part , an open mike in 2011 caught his complaining about having to deal with Netanyahu , and Obama did n't meet with the Israeli leader when he visited the United States last fall . Obama cited a scheduling conflict . At the opening news conference Wednesday , both men were demonstrably friendly in exchanging handshakes . Israeli president : No doubt Obama has Israel 's back . 2 . Iran 's nuclear program . Netanyahu pressed Obama last year to draw a red line on Iran 's expanding nuclear program . Obama indicates he has wiggle room before Iran 's nuclear capacity crosses a line , and he is expected to urge Israel to give diplomacy more time . While open to that idea , Netanyahu adds that diplomacy has yet to deter Iran and will press Obama on committing to military options against Iran . Obama said Wednesday there was still time for a diplomatic resolution to the situation , but added that each country has to make `` the awesome decision to engage in any kind of military action '' for itself . 3 . Syrian civil war . As Obama began the trip in Israel , he reiterated his warning to Syria 's government that it would be held accountable for the use of chemical weapons `` or their transfer to terrorists . '' The warning comes amid allegations by the Syrian President Bashar al-Assad 's government and rebels that each used chemical weapons in recent fighting . `` We intend to investigate thoroughly exactly what happened , '' Obama told reporters Wednesday during a joint news conference in Jerusalem with Netanyahu . Doubts expressed over chemical weapons claims in Syria . The president said he was `` deeply skeptical '' of Syrian government claims that the opposition had used chemical weapons . Obama has previously said Syria 's use of chemical weapons would cross a `` red line . '' `` We have been very clear to the Assad regime -- but also to other players on the ground -- that a red line for us is , we start seeing a whole bunch of chemical weapons moving around or being utilized , '' he told reporters . `` That would change my calculus ; that would change my equation . '' 4 . Peace between Israel and Palestinians . Expectations are zero that Obama will broker peace between Netanyahu and Palestinian leader Mahmoud Abbas , who have yet to return to the negotiating table . Still , Obama will visit Ramallah in the West Bank and meet with Abbas and Palestinian Authority Prime Minister Salam Fayyad -- if only to highlight the distance that remains for a two-state solution for Israel and the Palestinians . 5 . Beyond the visit . After Obama visits Israel , the West Bank and then Jordan , new Secretary of State John Kerry will likely remain behind in Israel and meet with Netanyahu on Saturday , a senior State Department official told CNN . Kerry would review the results of Obama 's visit and discuss the next steps on key issues , the senior official said . Such a follow-up strategy would mark Kerry 's first foray into Mideast peace issues -- and could advance any success Obama achieves during his maiden visit to Jerusalem and the West Bank . Opinion : Obama 's Israel trip is about legacy .
NEW : President Obama warns Syria 's government will be held accountable for its weapons . NEW : Obama makes his first visit to Israel since entering the White House . His relationship with Netanyahu has been chilly at times . Obama will urge peace talks between Israel and the Palestinians .